They can't. Because they have to constantly dial up the danger to mutant kind for the sales that the franchise ended up in the situation. But at the...
But doesn't HoX/PoX establish the timelines of her previous lives are erased after she dies? We know in her 6th Life that Homo Novissima specifically...
Interesting, that's actually (according to a google search) Claremont in X-Men True Friends which (from the thread I linked) was part of his buildup...