Seat tracks
All the seat tracks I have seen are fixed and do not change with seat config. The track is part of the structure and it would be prohibitively expensive to move them. It would be much easier to move the attach points on the seat assemblies to fit the seat track on the floor.
The seat tracks transfer all the G loads from the seat and contents to the aircraft structure. Usually stressed to about 16 gs if my memory servs me correctly.