To me Bionicle being introduced would be perfect, as it would open a whole new realm of possibilities, basically every single system blocks theme had run time in the movie: Castle, Space, Ninjago, Star Wars, Batman, etc these are all main themes that ran for years, and still run. With the Lego movie 2 having introduced mini dolls, Duplo, it just makes sense for Bionicle to be next. Anyways with Universal's takeover we have no idea what to really expect.
They scrapped Takanuva from the Lego movie 2: