^^ I think Arum will have to make that fight for Beterbiev, it could be Arthur's last fight for all we know and he may want to get out with a bang and become a unified champion at Light Heavyweight. And with Bivol not having a good dance partner or at least building his momentum after winning against Canelo, he will need Beterbiev at this point.
So it boils down on negotiations, but then again, as we have said, if the Saudis are willing then both of this camp can sit down and talk and all agreed for this big fight again in the Middle East. They just need to heal their body as they come from a fight and then Beterbiev will go after Ramadan.
It is easier to decide to clash when there is a Saudi prince right in front with a pile of cash. Ngannou has become their favorite as of now, whoever fights with him, I think will have to happen in Saudi as long as they are as big as Ngannou.
Beterbiev is a Canadian though and he will likely be inviting fighters to be in his country as they can host a big crowd. Unlike Ngannou who is from Cameroon, a poor country that probably has no arena capable of making rich men sit comfortably to watch him fight.