I would create one, but unfortunately I don’t know that I would have time to properly moderate it. I haven’t heard of a mascot one (I personally wish I could find one of women in prosthetic makeup (animal or creature), but I know that’s not a super popular thing, though animal costumes and prosthetic makeup could easily be a part of the same discord: TF in real life) but I’ll keep my eye out. Here’s the closest thing I’ve run across to what you’re suggesting
https://discord.gg/UA7aPD
It’s the discord for WackyWildAds, a blog that’s slowly become defunct as activity moves to the discord. I do like that this discord keeps its fanart, role play, and stories in a separate section called “community”. It’s similar to the idea you described, but I imagine it could be better organized for our purposes into specific categories (Movies, Tv, YouTube, music videos, commercials, social media effect filters, content creators, lost videos, behind the scenes, etc...). Heck, maybe the whole thing could just be “Female TF in the Mainstream” and we could include Costumes, Mascots, and Makeup as their own separate channels. At the very least, it’d be nice to set up something for this community if the site ever goes down.