Without the Super Emeralds, that's the only way that Sonic can ever turn to Hyper Sonic and also, since they are located in the setting in Sonic 3, I doubt it if they will ever be a future Sonic game again featuring the exact same place where to retrieve the Super Emeralds for Sonic to transform to Hyper Sonic. Well, that's my thoughts about it unless something changes soon to allow Hyper Sonic to appear again, I don't know...