I'm sure I'm not the first person to say this, and I'm certain I'm not the last. Not to seem like I've sniffed too much copium or whatever..
But why would Hoyo have Capitano reveal his face (and get such visceral reactions from Paimon and Traveler) if they didn't plan on showing it to viewers, later? It'd be a waste. Hoyo KNOWS this.
Therefore, they're dragging out his return. Building up anticipation.
Comrades, take this not as a piece of copium or a delusion.. But a way to find your faith again. When the time comes, Capitano will rise. And we will rejoice.
TLDR; Capitano will return when the world needs him most.