As others have stated, I don't "rotate" carry guns, but I do switch off based on circumstances.
It used to be "common knowledge" that magazine springs would soften over time if the mags were kept full and the springs didn't have any time to relax. Maybe that's the reason some people say to "rotate".
I think back in the day the springs were junk but today's springs don't seem to have that issue (if there ever was an issue).
Or maybe it had something to do with corrosion. Gotta give the gun a break to soak in some oil before putting it back into service.
I don't know, just spit-balling.
Most likely "being put into rotation" was someone's way of saying they "switch off".