Louisoix and Nael van Darnus are gone. Reason why they're on the official website is because new players need an SE source (not a forum based source) to know who Louisoix and Nael van Darnus was, course 1.0 players returning also need this. Of course if SE decides to go down that road...everything is made out of aether, if someone dies and the aether returns to the flow...they could be born. But for Van Darnus he was absorbed by Bahamut, so that take that for a grain of salt but I'll say he's gone. He'll probably most definitely return in Echoes though.

As for Louisoix being Odin, for me it'd be odd if a person can turn into an Elder Primal. Their aether can be consumed by the Elder Primal/Primal but I really doubt he just upped and changed into Odin. If he had that power he could have combated the Garleans himself.

Also I still think the Daybreak blade is actually us.

But all is not yet lost. Sensing the gravity of the situation, our master--the Allseer--has arrived to begin his search for Daybreak--one of the valiant blades mentioned in the Divine Chronicles.
Ne'er till land consumes sun can sea bear moons.
Heavens spew crimson fire. Hell seeps black doom.
Stray seeds quicken in ash's grey embrace.
Valiant blades forged under the Twelve's good grace.
People are always misinterpreting prophecies and translations, Louisoix didn't realize the Daybreak wasn't a physical sword it was us, the Adventurers who would become the Warriors of Light. Or maybe Louisoix knew it was us (after all those quests) and the Circle of Knowing (Y'shtola, Thancred, and I think Papylamo was the one in Gridania) were the ones who misinterpreted and thought it was a physical blade.