So the SHs left without saying goodbye to Kinemon or Momo either. Guess Luffy doesn't care about them, huh?
I wonder if we'll get their tearful thanks and goodbye this chapter or next, but it makes sense to isolate them for their own goodbye because of how long they've been together. They both have earned their keep, just as much as Vivi had.
It's been a pretty big plot point that Yamato has never set foot outside of Wano via the Oden flashback. My guess is that Luffy will make a dare for Yamato to jump off or declare a desire for freedom, similar to Usopp's apology in W7. Gives some focus to the character rather than just being on the Sunny with no fanfare.
As for the Guardian Deity thread, it's clear from last chapter that Momo does not recognize it or want Yamato to stay. Instead that may be a void century link where Yamato's DF was a guardian of Old Wano instead of New Wano, thus a need to learn about the true history. Or it could just be a one-off Kaido dream that needs no explanation.
Regardless, I think the thing everyone will be looking forward to this week is which Carrot fans graciously take their L like they promised now that it's confirmed Carrot is not joining, and which ones still throw a tantrum.