Keep in mind that the structure of the Senate Don't give the majority leader nearly as much power as a lot of people believe.
The Senate is largely majoritarian, so the leader can only really do what most of the Senators will allow; he's bound by the wants of the chamber
So if he's giving such a vote, it's reflecting a general sense among senators that there should be one, for whatever reasons, political or strategic.
A simple majority senators could override him though. If most senators want to have the vote, they can call for the vote.
He might be pushing for the vote to out senators who want to vote in favor of it.
@volkris He has the ability alone to not bring the vote. He's supposed to know his party line stance. This is a stupid consideration considering Biden can make these promotions as acting positions..