Why do you think bloodraven stayed loyal to daeron? Loyalty? Or he just couldn’t be on the same side as bittersteel?

Well, we still need more data, but my guess is that A. he felt loyal to Daeron for saving him and his mom back in the day, B. he distrusted Bittersteel and his followers who were surrounding Daemon, and C. he may have thought that, whatever his own personal feelings about Daemon and Daeron, that Daeron was better suited to be king.