I’m trying to piece the entire retcon together here, probably an ill-advised task.
A while back we learned that the Plutonians had sucked out (snorfled?) Trump’s brain in 1989 and had a remote-control unit in Trump’s body so they can control the Presidency. However, since in 1989 Trump’s brain was in Bill the Cat’s body, they would have done the switcheroo there, but when the Russians later helped Manafort retrieve the “brain” (replacing it with curdled borscht) nobody noticed it was a Plutonian remote-control unit.
The Plutonians came back and snorfled Bill’s brain (curdled borscht at that point) but he seems to function fine without it. In all these surgeries they missed the prefrontal cortex, but even with that removed, Bill is still functional.