The main issue with Brahms: The Boy II's big reveal is that it completely reframes the original. The twist that the real Brahms was alive and there was nothing supernatural is what made it work, but The Boy II bizarrely goes out of its way to undermine all that.
Bell continued that the next movie will reveal that Brahms Heelshire survived the events at the end of the first installment, and that it will reveal what he has been up to; while expressing plans for the character and his doll counterpart to appear in the film.