Especially when I read the interview with Yoshi-P commenting on why Zenos is reaper, this quote makes a pretty interesting implication:
“Zeno’s only friend is the Warrior of Light so in that respect maybe his avatar is some sort of variation of our Warrior of Light." I wouldn't be surprised if his avatar is the shard of our soul from the 13th, the Void; this seems to be what Yoshi-P is implying anyway, (could be intentionally misleading us though!) so another re-joining of our soul would likely come from this if my speculation is correct. Especially as there is no way for us to re-join with that shard otherwise as far as we currently know.
I think as far as awakening goes, we'll probably get a re-joining power up, maybe master the echo finally and get more information about Azem's decisions etc. but any more (becoming something akin to an ascian/ancient of some description) would possibly alienate players from their characters. Plus I think Azem's example of venturing the path less travelled matches with our current wol's personality in MSQ anyway, and us following their lead instead of becoming them is pretty in keeping with Answers lyrics "Look to those who walk before, to lead those who walk after". This is just my tin foil speculating though and I think it could go either way, (as well as ways we couldn't even know!) but whichever way it goes I'm sure the writers will make it very compelling and interesting!