What the fuck else are they supposed to do with mutants now?
The whole deal with mutants was that, barring special cases like "threat or menace" Spider-Man, mutants were the superheroes who were hated and feared by the general public, but in the wake of "Civil War," ALL superheroes became hated and feared, which left mutants with NOTHING TO DO.
It's like the Punisher in the '90s - DC and Marvel both went through phases, during the 90s, of trying to turn all of their characters into the Punisher, and yet, ironically enough, the Punisher's sales in his own title fucking CRATERED, because by being imitated so much, he was ROBBED OF HIS NICHE.
ALL superheroes are now as wangsty and persecuted as the X-Men once were, so unless Marvel actually wants to make things BETTER for the X-Men - unlikely, since DC and Marvel believe that things should ALWAYS get WORSE for superheroes - then what the fuck is left for the X-Men to do?
In a way, it's a perfect metaphor for the status of the X-Men ... they've devolved into this irrelevant, incestuous island of characters and concepts already completely cut off from the rest of the Marvel Universe, so why not make it official?