I wonder if they'll ever bring back Mr. Freeze for a live-action Batman flick?

Probably not. Especially since the dark and gritty Batman films of the past 20 years have featured villains they can do realistic takes on without being campy or cartoonish. This would be difficult to pull off with certain members of the rogues gallery such as Poison Ivy, Clayface and of course Mr. Freeze. That's one reason... the other possibly being the tarnished legacy left behind by Arnold Schwarzenegger's infamous portrayal from Batman & Robin. How do you even redeem that character for the big screen after those unrelenting ice puns? 😅