To be fair, supporters of those characters did go through their characters getting deconfirmed. I won't front, I think Isaac fans will be no different, it's human nature to be disappointed when you've invested so much time/hope into something.
If we're in the timeline of an Isaac deconfirmation, I just wished it happened when Lyn/Waluigi/Ashley/Krystal etc. got deconfirmed those early months. People were upset, there was a bunch of drama in social media, and now people have moved on and sometimes I forget that Waluigi had this big thing over his deconfirmation most of the time.
Isaac on the other hand is another highly requested character who's playable status has been dragged out so long, we're closing in on learning the last reveals for this game, so the aftermath of his deconfirmation will be the most memorable and talked about compared to the above fanbases in which case I'm sure people will joke about how the Isaac fan base is 'Chill no more LOL'.
That's just the only thing I hate about that generalization, not that it isn't great to be refferred to as, but it's annoying feeling like you're shoehorned into this nice guy type of generalization and if we act outside of that hivemind it's taken out on the Isaac fan base as a whole. Like mentioned I just find it silly that cause I'm an Isaac fan, I have to be thought of as chill. I mean I am here, don't catch me on YouTube and tumblr though lol.