I'm really doubting there are any guest characters after the panel at C2E2
1) if they were gonna announce a guest, it would've been at C2E2
2) Boon was asked at the C2E2 panel about the effort of getting guests for MK11 and it seemed like he didn't have an answer— the moderator had to ask him to talk about previous games and then he was able to talk about it, and even then he made it sound like a pain in the ass
Yeah i can imagine licensing and also making sure there balanced being a pain in the arse, and too much cost. Id vastly prefer the 6 characters to be 3 old characters and 3 brand new ones.
They could do what they did with MKX and make a second season pass that is guest characters.