After the way Yoshi-P imitated Neo from the Matrix in the Live Letter dodging Zenos questions, I'm pretty sure he's not dead. And Yoshi-P raised some interesting ideas on whether we saw what we thought we saw with his commentary that what we saw in Ultima Thule is shaped by our perceptions. I didn't play XI but from what I've heard described of what dynamis was there, it seems to fit that idea.

So it may not be a matter of bringing him back. Things may not have gone down how we think they did.