Thank you for explaining what O.P meant to the understanding of everyone about what an I.P game means, and as such, I would have also like to ask, How will the profits be generated form these IP games? Since the majority of the IP games you suggested are all adventural games, such as Spider man, Sega that makes somehow entertaining, and wants wants to play more, unlike casino games are are designed basically for profit maximization.
Honestly, this question should be directed to the OP, he might have more idea how everything would work. In the meantime, IP games and the original owner of the brand must have an agreement before game providers use their characters to create a casino game. If game providers do it without seeking the consent of the original owner of the characters they may be sued to court.