This has been discussed a bit previously. Bambu does state in their marketing material that the lidar and force sensors both are used in ABL, although no technical specifics have been supplied.
Dual automated bed leveling for doubly guaranteed prints.
Bambu Lab X1 utilizes two sets of independent sensors and an algorithm to measure the height of the nozzle relative to the bed. The lidar and analog force sensors crosscheck for an extra layer of redundancy in bed leveling.