But now the golem is turning on its master and she gets all pissy that they're coming after her for not going along with troonism.

Absolutely, but I think it's not really trannies that Rowling opposes, but men. I've followed her on Twitter/X for awhile and can't remember a single instance where she condemned FtM trannies. It only seems to be MtF that she cares about. She often doesn't mention transgenderism at all and will instead specifically refer to "men in women's spaces."