From what we've seen so far, it's possible that dive or whatever ride they call it could come back.
Kukui's fish tank shows that they already have underwater scenery as well as swimming lovdisc and corsola in the game. Sharpedo is the surf equivalent mon, and they already made diving models for it in Oras. One of the three observable beaches on the first island has darkly colored water patches whereas the others have plain light surfing water. Finally the anime, while not to be used as concrete evidence, shows ash both surfing and diving with sharpedo.