I was aware of the Game Porting Toolkit announcement. In fact, I first learned of it from CodeWeavers, who noticed Apple used their code to develop it.

We are ecstatic that Apple chose to use CrossOver’s source code as their emulation solution for the Game Porting Toolkit. We have decades of experience creating ports with Wine, and we are very pleased that Apple is recognizing that Wine is a fantastic solution for running Windows games on macOS. We did not work with Apple on this tool, but we would be delighted to work with any game developers who try out the Game Porting Toolkit and see the massive potential that Wine offers. Our PortJump™ team has perfected the art and science of creating ports of Windows applications using our Wine technology, and we welcome inquiries about how we can help get your game working on macOS.

I don't play games on macOS, but my understanding was the same as yours; that it was a testing tool for developers to test out how the game might work on macOS. That's how it was presented. I didn't think it was meant to be used by macOS users.

In any case, CrossOver is intended to be used by macOS users (and the GPT uses the same code, as enthusiastically explained above), and it has a good graphical interface. I think these factors make it obvious to recommend CrossOver as the canonical solution for playing Windows games on macOS.