If he comes back, it will ruin the whole story, and the idea that our guardian is slowly drifting to the darkness. If they bring him back, then there’s willl be no story for Uldren. We wouldn’t still hate him, because there would be no need to.

Cayde-7 The Traveler has been dormant for a very long time. It’s now active. It could just bring back Cayde-6’s ghost. Then, Exos do their thing. Cayde loses some memories but is otherwise back to his post. To break the fourth wall however, the issue isn’t whether it’s POSSIBLE to bring him back. The real issue is that Nathan Fillion is no longer available to record lines for Cayde-6/7.

I would love to have Cayde back, but I just don't see any way that they could do it without basically destroying the lore of the game. Like if they can bring Cayde back, then why can't we bring back the hundreds of guardians who died during the Red War? Like maybe if Cayde was brought back as a new exo that could be cool. But I really just can't think of any way he could be brought back that wouldn't destroy the lore.