The only good recent face-heel in the X-Books is Magneto because he barely "reformed" anyway, so his new trajectory wasn't that drastic of a change, it was a long arc filled with character stuff, and he's the franchise's best antagonist, so there's a stronger reason to put him back. The problems with it are general recent X-Office problems like him deciding to make his big return to the main stage in purple underpants and that his new Brotherhood will be ignored to the point that they might as well have not printed that page.
Otherwise, the X-Men's bad rogues gallery problem needs to be solved by doing new things, not trying to recreate 1991.