>>7760428DC and Marvel have no shortage of characters so I don't see why they need to do others. Both of those are unlikely for different reasons. Hellboy because the recent movie sucked and not enough people are interested, and because Sentinel just made a full-on action figure. Spawn because even if the new movie does amazing, McFarlane won't license it out to, especially now that they're willing and able to make modern style action figures. Sure Japanese market, price x3 more than theirs so why care, but he doesn't want to see others make better figures with his creation, especially in the same scale and materials.
I don't think AY will go to other Western publishers for capeshit. Like Optimus (AY team considers it part of AmeComi) they might pick long existing beloved IPs and promote the AY as comic ver. just to differentiate from past figures. IPs like Robocop, Terminator, Aliens, Predator, TMNT, etc. 80's stuff, for nostalgia.
I still think AY will keep expanding into Japanese anime and games and not other Western comics, but maybe TMNT could happen. Kaiyodo did before so getting rights again is probably easier, and if Yamaguchi sculpts them smart, could make all 4 turtles with mostly common parts. Maybe sell some more Batman by emphasizing the crossover in the promo material.