I actually know a dev on this project. She is rightfully mortified at Rowling's comments and is deeply conflicted.
However, one thing is fully clear: sales of a game almost never go to individual developers of the project. Sure, maybe if we had better unions, this would be a slightly more complex issue. But it's not. Sales of a game determine future decisions about the IP, and the profit pages on a corporation's books, but it's very unlikely that the success or failure of this game, in this case, will cause layoffs to a well-established development team, *especially* if the game is competently made but simply didn't do as well due to the extent circumstances of JK Rowling being a massive piece of shit.
Supporting LGBT charities directly, with cash, is one of the best things you can do, but sending a message to WB over this game is certainly a good way to support your trans allies as well. Frankly, if one of my trans friends found out I was breezily enjoying this new title, I would feel like an absolute shithead.
So I won't.