I can pretty much already picture a scene where MC hears a prayer in his head for the first time from one of his followers and is shocked about it.That's a solid point. Makes sense that the island not only gives him new powers, but also gains him followers who hold him in reverance. Especially if he can unite the tribes.
Hadn't considered this boosting his power, though. Definitely makes sense if that's where this is leading.
Long-term (like end-game epilogue), I fully expect MC to become a literal god akin to Maia, who was essentially originally promised to be the god equivalent of his wife based on a few bits of dialogue.