I think so too. He's 37 and maybe has like 4-5 fights at the highest level left in him, so he probably wants to maximise the profit before retiring and won't be much interested in fighting some average fighters from light heavyweight.
His next opponent should be Ankalaev, assuming he beats Rakic. So Alex could either escape the Ankalaev fight by moving up to the heavyweight, or fight Ankalaev and then (if victorious) move up to fight either Jon Jones or Tom Aspinal. But if he was to lose to Ankalaev and move up, he unlikely would get a shot for the belt and would have to fight someone lower-ranked first.
Anyhow, there aren't many interesting options left for him in the light heavyweight. But then again, the UFC matched him up against Rountree, a fight that no one expected, so who knows what they will come up with next.