I'd like to see the Deku Scrubs come back after being so prominent in MM. The Deku Palace was a neat idea overall and I think having a small area where the scrubs live (kind of like Korok Forest) would be interesting as well.
I would prefer personally for at the very least a civilized Deku Scrub race with more character development for one that would befriend you similar to the other Champions
I just want to see more work and love put into these little guys
I have a feeling Nintendo's going to bring back old races, characters, etc. from past Zelda games. It would add newness while also adding nostalgia points. They were going to add the Minish according to an interview, and almost made a kokiri a Champion in the concept art.
Also, adding the Kokiri or any other race to further prove the bull****-ness of the timeline would be so funny and awesome. XD