I wonder if the article is about Sublime discourse on Twitter lmao.
So bl is a super popular genre, but people who did not seek it will probably won't know about it much, but it is a very large industry.
The main popularization and most well known bl's came from Japan (the pioneer I can say), Korea, and for those that didn't know it might be surprised, but china is also one of the largest contribution for bl's popularity despite the censorships in it's media. MTL like Google translate has come a long way, but Japanese & Korean translation is still far off, while it's improves massively in the past few years for the Chinese language so it's of no problem to just MTL danmei (bl genre in china) and just read them.
I don't think Americans gay novels have that overly popular status like the one on the Asia but there's some that popped off too like heated rivalry (I have never read/watch those unfortunately) and the like.
I personally consume bl almost every day. I might have a problem tho, but I do read a lot in daily basis mix with others genre.