Yes. Any Administrator can go to to Access > Apps>Seat Management to reassign a seat. First remove it from the user who no longer needs access by selecting their name in the Assigned Members grid, and clicking on Revoke 1 seat. The seat is immediately freed. Then assign it to the new user by finding them in the Unassigned Members tab and selecting Assign 1 Seat. Seat reassignment is immediate.
Can I reassign a seat from one user to another in ChangeGPS Seat Management?
Explains how seats can be reassigned between users and how access is updated