Of course she was still part of the brotherhood. And what other details do they need to go into? They said he's not her father, that she was experimented on by the High Evolutionary rather than a mutant, and that's like, the whole retcon. It only retcons her origin/background/birth/very early childhood. None of her appearances have been erased from canon. They wrote her being glad about not being Magneto's daughter, which makes no sense if her history with him had been erased.