Well, if he is open to fighting Canelo Alvarez I think that is good enough but yeah a Unification title fight would be great aswell for me Artur Beterbiev is a bigger threat to Dmitry Bivol than Canelo Alvarez it could dirty his clean record and I really don't like that to happen, but for the enjoyment of all It will be a crazy fight,
According to some replies the fight with Canelo would be more possible to happen since Bivol - Beterbiev is somehow impossible due to boxing politics. It is a sad thing that even sports is greatly affected by politics. So we will be missing this Unification fight until the problem with their promoter is fixed.
Sad but true, this is not the first time though, boxing politics have been with us decades already, it's just they are more magnify right now with all the managers tying up with networks like Sho, ESPN and now DaZN, so it makes it's impossible to make big fights because it's business as well.
If ever both party agreed for a rematch, I wonder which weight Division are they fighting, would it be Canelo's division? or Bivol's division? If ever Canelo go up in weight division just to fight Bivols in his natural Division, I think we will be seeing the same result like their first fight.
I don't think that Bivol can go and fight at 168 lbs, he has been a true light heavy weight fighter in his career. So most likely if Canelo insisted at this comfortable weight, Bivol is not going to take the fight. Canelo has 2 fights already in light heavy weight so I guess there is no problem for him moving up again and rematch Bivol. Although the result might still be the same as you have said.