Well, correct me if I am wrong but as long as I know Bionicle was ended in favor of HF because of the overly complicated storyline that Bionicle had, which explains the much simpler story of HF and the episodic nature of it. This probably means that Bionicle 2015, although keeping itself close to the "roots", will probably be also simpler in terms of its new lore. This can be seen already in what we know of the new Bionicle, for example: calling the toa "masters" of their elements so their role is easier to understand for new fans, etc.