You can't really read anything into that. As has already been noted by law there can be no more than 3 commissioners from the same party. Traditionally when a

You can't really read anything into that. As has already been noted by law there can be no more than 3 commissioners from the same party. Traditionally when a commissioner's term expired and they were from the party that did not control the Presidency the President would ask the other party's Senate leadership who to nominate and would nominate that person. Also traditionally the Senators of the President's party would vote to approve that nominee. Biden followed this tradition, as did the Senate Democrats.