The issue is that the problem is with the timing that people have been having since 6th came out. Which comes first, Reserves or Blessing/Maledictions? Same thing here.
The Tervagon has not *actually* moved, because the movement phase hasn't happened yet, it just can't after it deep strikes. And the quote you have for shooting phase? Well, that's shooting phase rules, and while it says it has moved, well, it has... but not in the normal movement that can definitively disallow spawning.
However, I believe there is a rule in the beginning of the rulebook (don't have it on me right now to give page number) that says that if multiple things are happening at the same time, the person whose turn it is gets to choose the order. That would imply that the Tervigon player could use the blessing to deep strike before movement, then spawn before movement.
However, without a definitive FAQ about this, I would say if you really hate giving the tyranids any sort of reprieve for having a subpar codex, roll off for it. :P