So have we discusesed the idea of the strange souvenir being transferable to Sun/moon? It has a tiki esque design so I think it was clearly foreshadowing this regions theme but I wonder if it will actually do something in this gen
I imagine you can't since you need Bank to transfer.
I think there's gotta be someway to at least have Sun and Moon recognize that you have it in X/Y. It's definite foreshadowing to some Pokemon in Alola. Now, whether that's simply the new games somehow recognizing data from X/Y or an update to the Bank for even just "special item" transfers, which I think is likely, the Strange Souvenir is going to come into play in some fashion.