

Minecraft has a long and storied history of cribbing features from modders and integrating them into the official base game. This includes hoppers, light senors, pistons, slime blocks, several of the types of trees, armor stands, displaying maps in frames, quite a few mobs, several of the current biome types, and probably a whole bunch of other stuff I can’t remember offhand.
So yeah, stealing the idea (even if not the outright code) from shader mods would be completely on brand, and not at all unexpected. It’s up to the player base to decide how they feel about this, but honestly it seems nothing short of kidnapping babies and setting them on fire would get any significant portion of people to turn away from Microsoft’s stewardship of the game, given how hard they’ve tried to screw it up post-acquisition and yet it continues to print them money.
Definitely not. Test Drive Unlimited 2 leaps to mind, which while it certainly had racing events and racing related content in it, you could also just drive around doing nothing in particular as much as you wanted.
There are several other racing oriented games that nevertheless had open worlds and you’re never actually forced to race anybody in any of them, albeit usually at the expense of sacrificing any game progression and thus having a rather limited vehicle selection. Need For Speed Underground 2 and Forza Horizon, for instance.