I bet that’s not gonna fly, legally. This is a tectonic shift in how they’re proposing to monetize their product. This is a unilateral adjustment to a contract which will have an immediate and negative impact on the other party. This will be challenged hard in court.

Yeah -- at this point I'm actively seeking out FOSS options for everything because it seems like literally every corporation wants to enshittify into a service at this stage. Will be interesting to see how everything plays out, if not just depressing.

More then that, there's basically zero way to enforce this for existing games. What are they going to do, forcibly update everyones already built games?

I don't think it's just questionable, but an attack on human art based on an out-of-control capitalism. And I hope this is just a bad-tasting joke from Unity. In Godot I don't see a solution, it's a program still with so many problems in physics, collisions and 3D dynamics that is supported by the community that changes the source code while the official developers are obsessed with releasing new versions on new versions. And I'm afraid that soon or later they'll give in to the desire to make millions upon millions on the shoulders of creators.