Rocket League runs great with proton, and in my testing, it ran better than the native version when it was still available.
If you bought it to play on a 32-bit Mac would they be obligated to port it to 64-bit? Would they be obligated to port an OpenGL-based client to Metal after Apple's deprecation?
You're telling me that because I can emulate the game it still exists. If I accept this premise than literally all games are linux games and the concept of platform goes out the window. It's absurd.
They're letting you play the game you paid for. I can understand being unhappy about the loss of a Linux client, but by all reports the Proton version runs better, so what's the actual problem other than your ideology? Epic is a corporation, not a religion.