The first time around, yeah. I watched the movie a second time last night, though, and... well, this time it clicked for me. The way I read Noa's role in the movie is that he acted as the Ultraman of that universe and Zero ultimately needed his blessing if he was to use his powers freely there.
Zero earns that blessing when he uses up every last bit of power he has trying to protect people from Belial's army. So just as Zero honored Ran's sacrifice, Noa honored Zero's willingness to sacrifice himself by giving him the power he needed to protect everyone.
This is more or less exactly what Noa does in Nexus, so it's even fitting if you want to believe that Zero's Noa is the same character (in some way) as the N-Project's Noa. I certainly like to think that way, though I'm sure there's some continuity footnote that makes it impossible.