Pokémon is an exclusive because you have to pirate it / break the console’s DRM to play it on PC. Also, Proton and Wine are explicitly not emulators - that’s actually what WINE stands for (Wine Is Not an Emulator). Starfield is natively available for more than one platform and not only does the Proton compatibility layer handle it but it’s being sold on Valve’s store and the top played game on the completely Windows-free Deck. Games that are released on one console and PC aren’t exclusives. God of War just isn’t on xbox and Starfield just isn’t on Playstation.
Do you need to buy a console to play it legally? If no, it’s not a game exclusive to that console. I have a PC. I can’t play exclusives like Demons Souls Remake without buying Sony’s $500 DRM machine. I can play non-exclusives like Starfield without buying Microsoft’s $300 DRM machine.