Very development meta, but you've also got to remember just how much money Bungie will have spent on Nathan Fillon. It's extremely unlikely that they'll have invested so much into Cayde's character without him being integral to the overarching plot, (and extremely out-of-typecast for Nathan to have a character, without it being central to the good guys winning - that's what he does, right?) The early Exo grimoire, TTK, his journal, etc, etc. Anything that connects Cayde to beating the bad guys is likely a sure bet. Chioma probably isn't anywhere near to the Sol system when the shit hits the fan during the collapse. Maya's a much safer bet. Wouldn't surprise me if Lakshmi turned out to be Chioma, tho.