Seems premature, they have not decided on the motion to intervene. That would be crazy if they granted en banc on the case, but denied the motion to intervene - who would argue the case? I am sure that would never happen of course.
I don't see Peruta going sau sponte, the CA9 panel wrote the opinion for the SCOTUS to review.
I will place a wager, the CA9 would love to clear their calendar of all the 2A cases with more guidance from the Supreme Court.