Don't worry about it. You're not collecting data from children.
COPPA is indeed a federal law. However really unless you intend to work heavily on Youtube its not a huge deal. It has been in place for awhile just only recently is being enforced. It deals with companies collecting information for children under 13 in order to specifically target advertisements to them.
I've made my yt private but I'm still on dailymotion. I've heard from other creators that inappropriate stuff were marked as for kids by yt because it's animated. The youtubers who are in the clear and know they won't be affected just keep saying that everyone else are just throwing tantrums because they're not popular enough. They don't understand the huge grey area and that it's not fair to punish everyone instead of those who broke the rules. Kids aren't allowed on yt but parents let them or they lie on their accounts .yt were knowingly gathering data. youtubers weren't and can't but now we have to play a guessing game because we are somehow responsible for their actions.it's ridiculous.
This is mainly YT throwing creators under the bus yet again. The reason they are even being looked into by the FTC is for their Kid's YT version.
The reason they are going to kid friendly on the main site is their own doing yet again due to bending over for advertisers. The ad companies themselves are so afraid of cancel culture they enforce this environment that everything must be family friendly for their brands. So bending to the whims of corporations they have made a more family friendly environment but those that choose to go without being monetized and use Patreon and other crowdfunding sources still keep mature content on so YT made the Kids version after the Elsa gate controversy. And this brought the FTC's attention into play.
For more info read about it all here:
http://www.coppa.org/coppa.htm3
tl;dr: Sites need to adjust how they gather and use data provided by people under the age of 13.
It's going to affect advertising and the algorithm that generates the suggest vids. (Which it should, their existing algorithm is trash.) It's because they illegally gathered information about kids viewing data.
I work for a kids entertainment company, so I've totally been researching this stuff. Here's a rundown.
Basically, Youtube creators are mostly doing nothing wrong (but some of them are). Youtube is doing a lot wrong, and they're trying to put the responsibility onto the creators.
So basically... COPPA means that companies shouldn't collect data on kids, like their name, address etc. There are also rules that kids shouldn't be able to private message or post comments or otherwise given opportunities to share details like their real name, address or phone number. If kids DO share this information, even if they do it by blatantly flaunting every rule and say, drawing a picture in an inbuilt oekaki system and carefully concealing their phone number in the picture (you may laugh, but this is a thing that happens on Popjam, for reals. Anyone who has or works with kids knows that kids are not always sweet little darlings, they can be manipulative and cunning little 
s), it's on the company, not on the kid that did it.
So... where does Youtube come in? Okay, so... to have a "grown up" (standard) Youtube account, you need an email, and youtube needs to collect the data of your email address. For that to be legal, the person must typically be 13+ years old (though this actually varies by country), which is seen as old enough to have the understanding to agree to give away that data and what it means to do so (kinda like getting your first proper bank account or doing a part time job, also things in many countries you can do at 13).
So for younger kids, Youtube made... Youtube Kids! ...Which kids over age like six don't want to go on... because it's called "Youtube Kids" (let's face it, if you were eight, you would probably see yourself as being grown up enough for proper youtube and watching the kind of thing your older siblings watch, just like when I was eight I wanted to listen to Alanis Morisette like my cool teenage big sister, not like... nursary rhymes or whatever).
So since the actual children who aren't pre-school age are on standard Youtube, companies like Lego and Cartoon Network have set themselves up on standard Youtube where the audience is... and here comes the problem.
So, Youtube has a bunch of people on their platform making content that is blatantly meant for kids, because everyone knows kids are using it, even though they're not supposed to be using it. Is that bad? Well, for Youtube... yes, yes it is. COPPA violations come at about $40,000 a pop, and usually if a person is violating COPPA, it's not just once. Companies have already incurred millions of dollars in fines just for things like not paying enough attention to what data their third party analytics software has been collecting.
If somebody can prove that Youtube is knowingly hosting content intended for kids under 13 on their platform, and has not made every possible effort to stop this happening, the amount that Youtube could be sued is... potentially astronomical. 
So their first action was to say to the bigger creators like Lego, "Okay no no no, if you're posting videos on normal youtube, they can't be for kids! We'll have to kick you off the platform if you do that!" to which those creators responded, "Ohhh haha noooo we're not making this for kids!", and so you get things like the Lego channel never addressing the audience like "hey kids!", never featuring any children in videos, never speaking about lego as a children's toy except in a context like "this would be a great present for your child, adult viewer!" ...basically, all the channels making kids content pretend that they genuinely believe that they, the Lego/Cartoon Network/Roblox channel are making content intended entirely for an adult audience.
But now it seems like that isn't enough any more, because it's so blatantly transparent. So Youtube now wants creators to say on their videos "THIS IS NOT FOR CHILDREN, IF YOU ARE A CHILD, STOP WATCHING THIS!" to put the onus onto the people making content because of their complete lack of ability to stop kids from being attracted to their platform, making illegal accounts and ignoring the alternative provided because it's just so uncool to older children.
If you don't do it, you shouldn't be the one to incur a COPPA violation, but it's possible Youtube could turf you off their platform for encouraging kids to their platform so that Youtube might incur one.
If it helps any, Neopets has been COPPA compliant for years; and though their content and user created content was HEAVILY regulated and limiting for many years, over time they just stopped caring as it was obvious they didn't have to avert children's eyes to anything remotely romantic or dramatic and they never got fined. However, Neopets doesn't use Youtube's broken ass algorithm that'll waggle its finger and make you a kids' channel even if your content isn't for kids(you actually get slapped into under-13 site restrictions if you admit you lied about your age on Neopets even jokingly), so yeah I'd be a little afraid ESPECIALLY if this goes into other websites.
Thanks for the super-informative reply! Although...I mean, if all that is the case, you'd really think YouTube would be leading the charge in trying to protest these ridiculous regulations, instead of caving to them...it sounds like they're being forced to choose between getting sued or basically self-destructing.
But then, I've heard YT isn't exactly profitable, so maybe they don't have any other options... =/
Its also really telling that Youtube just recently (in the last couple days) changed policy to pass the blame on to creators. It is tiring to see YT destroying creators for the companies mistakes.
They sadly seem to be doing it often for every single little setback and flack youtube gets. I understand that the content on Youtube is (mostly) made by creators, but there are a lot of people who are using the platform as they should and not creating hateful content, but are punished severely or impacted negatively for things that are REALLY beyond their control.
It kinda makes me wanna avoid youtube. I don't do anything art related on youtube, but my husband and I do Warhammer 40k battle reports and he posts them on youtube. We're small time schmucks not making money at all. Still worries me.
What more, from what I understand, if you mark your content "For kids", even if you didn't plan on monetizing, your videos won't have comments enabled, you won't be able to use the community posts, people won't be notified of said videos and it might not even be searchable. So like what's the point of uploading anymore? Art vids and anything in the gray area could potentially disappear altogether.
Yup. I would like to say that youtube is shooting itself in the foot...
BUT I am not sure of other video posting alternatives that have the same platform base and globally known name. Perhaps Twitch? For art streaming there is Picarto, but I am not sure. I admit that I am unfamiliar with the impact of COPPA.
Pretty dumb, You make your content for adults, "swearing, or horror(especially horror), nah demonetized think of the children. Now you make your stuff for kids(or some can think its for kids) and nah you cant do that, think of the kids. Youtube kids is a thing you know...this just make youtube nonviable to everyone, except big companies who will never take the hard hit(see so many sexualised music vids). Mixture was competition for twitch and the only competition for youtube I can see is bitchute, but most of the content there is just far-right political videos.
I think the most threatening thing is where to draw the line to define what exactly is for kids. Especially when it concerns properties that appeal to both adults and minors, like anything Nintendo pushes out. And context is a really big factor, but bots sniffing out offending vids can't detect it.
