I'm sure you think AJ is the A Side if he faces Fury as well. If Canelo was the A side then Bivol would have took his pay cheque and made the fight for a lower split despite already beating him.
The winner of Canelo Charlo will most likely fight the winner of Benavidez Andrade next. Bivol can't fight Beterbiev because 1) Beterbiev is injured 2) Beterbiev has to fight Callum Smith first 3) Bivol can't challenge for Beterbiev's title. Canelo Bivol 2 could happen in 2025 after Canelo's 3 fight deal with PBC is complete. Hopefully by then Bivol will have an opportunity to unify vs Beterbiev and Canelo will have fought the fights the fans wanted vs the best PBC has to offer.