You'd be horrified by my brother's Final Fantasy X based campaign. The classes are completely divorced from the world. We've come to the point where we had to decide the classes (mostly) don't exist in the world.
If they were to do an Eldraine book, I'm sure they follow the "camelot stuff is the bulk of the cake, fairy tales are the icing" philosophy they mentioned guided the set.
There are a lot of "modes" (they call them formats) in MTG. But the magic sport is just a background detail (that presumably will be represented on some cards).
Edit: I just realized what you're thinking of. MTG doesn't have single player modes like Hearthstone does.
There were people who thought he was a flat out bad choice for the Joker.
I'm curious to know what actors they could cast that would inspire confidence for the movie in you.
Considering WoTC is downplaying alignment even more in the future (after already heavily doing so from the start of 5e) I don't think they are too worried about how DS affects the alignment grid. And they've been pretty clear that Lawful Good includes opposing unjust laws.
A lot of the problems...
Dark Sun, Planescape, Spelljammer, and Dragonlance are the top candidates based on popularity, references in released products, and information out of WotC. Curveballs are always possible, of course.
Edit: And I guess Greyhawk. For a top 5.
Dark Sun will have something about running desert or more hardcore survival adventures, I reckon. Spelljammer tips about space travel or something. But neither setting is as broad with their genres (which is really sword and sandals for Dark Sun, though I get where you're coming from with the...
It's the same format as every released 5e setting. They've already publicly committed to multiple classic settings. I think we are past the trial run stage.