Then Batman came out followed of course by Batman Returns. Sanity (such as it is in the world of fandom) returned. And then ... it was announced that Michael Keaton would NOT be returning for Batman Forever. And I shit you not, those very same "he has no chin" people were now jumping up and down and screaming at the top of their lungs "NOOOOOO!!! How DARE you?? Keaton IS Batman! No one can replace him! You fools! You've ruined everything! Boycott, Boycott, Boycott!"
Yeah, I remember all of that as well. People were very skeptical of the Burton/Keaton Batman when it was announced, then upset when they left. But quality product tends to win people over. It is a shame that The Flash film didn't do better, I honestly thought they did a decent job with the "We've seen some of these other worlds/timelines Bats and Supes and WW" - just hit it enough for fans but not make a big deal out of it - and the idea that Keaton Bats would be around for a bit was going to be fun I thought.
I will say that when the recast to Kilmer and Clooney occurred, those films were also not as well received (too campy Burton kept the camp to a minimal level while being quirky - hyped as much for the all-star actors as the bad guys...) but the Kilmer one did make money. So hard to know if better films would have glossed over the recasting more.
Yes, other actors can play Steve Rogers, Tony Stark, Thor Odinson and Bruce Banner. Other actors can even play Indiana Jones and Captain Jack Sparrow, blasphemous as that may seem to some. Yes, there'll be jumping up and down and screaming and wailing and whining. There may even be picketing. But do you think any of that will matter if Disney thinks there might be money to be made?
I agree, we will see IM and Cap again - I even look forward to that - I just think the smart move for them would be to hold off and disconnect from the current MCU, not be tempted by "let's find Earth 799 Tony Stark and bring him in" - unless they want to make the story about how we get a hero Tony Stark who is not accepted here, has to start over, can't find his place - that could be an interesting story. (I am still not going to be shocked if Doom is a Stark from elsewhere).
I will say that Disney more than most studios plays the long game with their IP. Cinderella (the Disney version) is 75 years old and they are still milking that and the Princesses. They like their continuity and love evergreen properties and I think may focus less on "let's put out a sequel/reboot" as once they get a character established they can milk it other ways - theme parks, cruise, merchandise, kids TV - better than anyone else. So I'd be very curious to know what discussions they have over the Marvel stuff.
I also believe integrating the Fox films via the multiverse serves multiple purposes - nostalgia and, fan service - but also retroactively making the older X-Men, FF and Spidey films a part of the MCU, which doesn't stick them in a box or irrelevance.
This discussion did get me thinking about Doomsday - at the moment only Dr Strange, Spidey and America Chavez from the core MCU have really seen other universes - Strange has met a Reed Richards and Prof X, we'll see how he reacts to seeing them again, given they tried to kill him. I expect him to be the defacto lead...given Spidey is an unknown to the world.