Since the announcement of 4th season i've been looking for more information and then i found a blog post by Debbie Moon where she said that while the cast of the 3rd season is in doubt, Aimee won't be back.

If this is the truth then i fear that even Bobby may be missing, since i don't see how they could run the show without Maddy now that she has been reunited with Rhydian, unless they can find some crazy mind-blowing plot development; so my question is shall we be worried already or i'm just over-reacting?

(I'll put the link of the post down below, you better see it for yourselves)

Debbie Moon blog post