We could use masking geometry to complete the movement in magnetostatic solver, that do not support motion.
1). Build a long rotor with material assingment, and magnet direction should be moving CS of ticking on "Move CS to end" in CS properties.
2). Add moving parameter on the whole rotor (moving parts), "Move" whole rotor and enter the parameter as moving value.
3). Build two regions (masking geometry) to cover outside of two ends of linear motor.
4). Subtract masking geometry from the whole rotor.
5). Set matching boundary with same vector
6). select "igonre Unclassified objects" in Maxwell 2D -> Design settings -> Validations.
After that, modify the miving parameter to check if model is correct.
There is in Ansys customer portal, https://support.ansys.com/KnowledgeResources/Solutions?solutionIdentifier=sol2043350&productName=ANSYS+Maxwell&productFamily=Electronics