Greg from the One Piece podcast dropped some really interesting info about Momo and his "meeting" with Roger. With the voice all things or the seeing of all things, Greg presumes that Momo literally talked to some iteration of Roger. I've got to listen to the Podcast to be entirely sure. It's fascinating because a couple things...
The breath of all things, is undoubtedly related to the voice of all things. Remember Zoro unlocking such an ability when he was on the verge of death against Mr 1. We know for sure Luffy has the full on ability even if he is unaware.
Think back to Jaya and the first meeting with Black Beard. All that cryptic talk about "not he" but "they" from Luffy and Zoro, promptly confusing Nami, she wondered if anyone else was with him. It was one of the weirdest scenes that Oda has ever drawn attention to. Later we do find out from Marco that Teach's body is different, which he assumes could explain why Teach was able to consume 2 fruits without dying.
I don't know how, I don't know why, but I think there is a literal entity of some kind attached to Black Beard. What ever the hell it was at that meeting, Luffy and Zoro noticed this, but to them it was just another person hanging around Teach. Something like this would explain the casual nature in which Momo brought up Roger, he thought he really met the living breathing guy.
This probably sounds stupid but I think I just blew my own mind!