If you are sure about what you want to do, why did you ask the question anyway? It's almost like you don't want advice, but validation. You know. Three people so far have told you that as readers it's weird to see such a theme whiplash, but you are willing to die on this hill. You do know.
I basically told you a text wall before the episode to explain what the reader is about to read is unsightly, too apologetic, too ungraphicky for a visual media. If you want to do a comic series about this or that then you could go for different topics, like comedy strips do, but in a serialization, where there's one timeline and a story takes place in one context instead of having several individual stories that could or could not connect at one point because it doesn't really matter, if you drop a strip that has nothing to do with the comic you're posting and gets no follow up, it's a serious whiplash that might put your readers off and might actually bring the overall quality of your comic down. Imagine you're a new reader, you're just clicking this story that has certain expectations to it, and then you get nothing but ads or a cat comic for weeks on end. People will totally leave. I'd personally think the author doesn't know what they want from their story.
On the other side, there is something to be said when you're working on a second season of something while at the same time publishing another story in that same space, people might wonder "Which is is then, why are you using your time on this tangentially different thing instead of actually working on the season and showing it to us?" Why does it have to be such a different topic than one from your story? At the very least it has to be side stories RELATED to your own comic. I don't see what you would like to promote another series, or a different comic, or just randomly post a strip of a cat. If you're not gonna commit to keep bringing that character back, if it's not part of the story's world in any way, then it's just clutter in your comic's index.
What old school traditional comics had that digital media needs not to worry about is limited space. If you have a very short story to share, there are numbers of different paths you could follow. A few panels can easily be posted on twitter or instagram or patreon. You could build your own anthology of unrelated stories. You could post it on its own and no one would mind. But if you're scared that it will somehow overshadow your main webtoon and that is something that you consider a bad thing, maybe you could desist.
Season breaks happen. Hiatuses happen. I work a full time job in which I draw for hours on end, only to go home and continue working on my own story. Sometimes I can't muster the energy after a long day's work. As a consequence, my updates are long, but sparse. I have lost 200 followers since my last update. It used to bother me a lot, but I understand that people have different reasons to do so. You will inevitably gain a few followers, lose some more. It's a tradeoff you need to live with. Or you can hurry up and release the next season ASAP.
