The Wanda/Pietro and Franklin retcons are all so easy to undo that they could do it in like a page if they wanted to -- just say Wanda/Franklin subconsciously reality warped them into not being mutants anymore but they always were.
Modern Marvel is so stubborn about not reversing unpopular retcons that do nothing for the fans. Wanda/Pietro, Franklin, OMD, America Chavez's origin, and so on. Back in the day if someone didn't like a retcon they just dropped it (see: Nova Roma). It's particularly annoying for Pietro who the Avengers line never seems interested in using and never uses well but has been a consistently good part of X-books when they get him since the 90s. Wanda could be used well in the X-books if they made her a mutant again but hasn't historically been.