I ran AC by the mile when I lived in CT. Here in central TX it's not allowed, so MC is used. Most everywhere I've seen the bushings used too.
I've never had a short due to moving a troffer, but once had to investigate after the HVAC guy felt a little tingle of current from the troffer. (Seems the snap-fit of those knockout plates doesn't really assure a good ground, and don't even get me started about the guys who just wrap the wire around the screw and don't tighten it down!)
What gets me (AC back in the day had steel armor, and yes, I learned to cut it with a hacksaw, circa 1994), is that MC with the aluminum armor stretches so easily. You install it carefully, and then someone comes along and bashes it. Then the armor uncoils, and all that is left to protect the insulation is that wrap of clear plastic that supposedly obviates the need for bushings. If that's OK, then what is the armor for? I think that's why they outlawed NM in high-rise construction, right?