That's a good question. I wonder if there are some mutants who would rather stay dead than be resurrected

I wonder if that will be touched upon in later stories?

I’m only caught up on most the first vols of the Dawn of X series, but I’m surprised they didn’t bring him back

I have read comics long enough to fully believe that no one ever stays dead, no matter what anyone says. Just have patience and before you know it..

Sometimes, dead is bettah

I spoke with someone on Instagram who apparently answered my question: supposedly, the mutant cataloging that forms the basis of the Resurrection Protocols began after Proudstar had already died. As such, neither his DNA nor his psyche was available for creating a new copy on Krakoa. He didn't have a source though.