Not an important thing, but they could give us something to do with the tiny and large mushrooms we find. LEt the move tutor be interested in both heart scales and mushrooms.
The Mushrooms existed in Gold, Silver and Crystal, and had no such use in those games (Hell, they could be found in Ruby, Sapphire and Emerald as well).
They were merely items that you sold for money. That was their original purpose. The only reason why they were converted into a "token" for the move-relearner for FR/LG was because Heart Scales weren't found in there (Luvdisc is a Hoenn Pokémon).
Anyway as for the new game, I doubt they'll make the third version radically different from it's predesscors. (Just extra stuff mostly. What this extra stuff is is anyone's guess).