Something I just noticed…
In SM, there are four different Z-Rings. The white one the player has, one with rocks in the bracelet, a black one, and one with what appears to be a leather band.
What I didn’t realize at first was that these designs correspond to the Kahuna who awarded the Z-Ring. Hala has the same white one as the player, and also gives that one to Hau; in the anime this is true for Ash’s as well. The one with rocks is Olivia’s, and Kahili also has this one, showing her ties to Akala Island - where her father’s hotel and golf course is (and she gave this same one to Kiawe in the anime.) The black one is owned by Nanu, Gladion explicitly states his identical black one came from Nanu, and Acerola has that same one too. The leather one is only owned by Hapu - whose ascension to Kahuna is witnessed by the player, meaning she has never given one out before.
Now consider this - the player character in the USUM teaser has a black Z-Ring. Hala could have redesigned his, but that would be unlikely since it would dilute the uniqueness of both his own and Nanu’s. This may be a very subtle clue that the plot of USUM is a radical divergence from the original SM, and Nanu gives the player their Z-Ring instead.
So I just assembled a bunch of images to prove that, yes, this is a perfect observation; I’m gonna include a bunch of characters missed in the original post.
For reference, these are the four Z-Ring designs:
First up, Melemele Islanders and their white Z-Rings:
(Hala’s is kinda hard to see under his sleeve, but hey, he’s the obvious one anyway. :P)
Next, Akala Islanders with the one decorated with rocks:
It’s worth noting that, in the anime, both Olivia’s and Kiawe’s are actually different, not only from the game design, but from each other. They’re still similar in concept, however:
Olivia’s is relatively close to the original design, except without the outer bands. Kiawe’s, however, belonged to his grandfather, the previous Kahuna of Akala Island, and has a band lined with what looks like lava rocks instead. Still rocky, but of a different designer, and therefore a different make.
Anyway, for convenience sake, I’m skipping to Poni Island, where Hapu actually did end up giving one of the leather-banded Z-Rings to Mina:
And finally, Ula’ula Island, with not only the previously mentioned members, but Plumeria and Molayne as well:
Aaaaaaaand now, the kicker:
That’s definitely Nanu’s design, down to the last detail.
I’m sure there’s gotta be something to it, but it’s waaaaay too early to be sure what.