I've said this before, I will say it again:
The guest characters ALMOST always represent an advertisement, either as a pre-release or as post-release.
MK9 had Freddy. MK9 was released in 2011, Nightmare on Elm St. came out November, 2010.
MKX Had Predator, Alien, Leatherface, Jason. The only character who doesn't fit the mold is Jason, as his movie was 2009 and he was a planned DLC for MK9 with Freddy. Everyone else had a movie within 2 years of the game.
For MK11 here's who makes sense: Pennywise It Ch. 2 (2019), Joker (2019), Spawn (filming June 2019)
Joker makes the most sense here, as he's already been in a Mortal Kombat game with MKDC, as well as being killed, fairly graphically, by Superman in the Injustice comics series.
Pinhead is another possibility as there was a direct to video movie in 2018.
Likewise, Michael Myers, since there was a Halloween move in 2018.
If NRS sticks to the mainly post-release characters, then Pinhead and Myers are good bets. Otherwise, Joker and Pennywise are pretty good guesses as well. Spawn as well since McFarlane has said how much he'd be willing to work with NRS.
