I disagree on this point and feel like Assembly is more descriptive than Body, as mentioned in previous replies.
After asking a few non-Roblox people, the word assembly seems more like a collection of singular things to them than Body does. Body, to them, seems like another singular thing, and not a collection. My sample size was low at 4 people, but seeing as most dictionaries also agree…
The terminology not being common on the platform, or not documented enough on the platform, does not seem like good enough reason to avoid it either. As a counterpoint: Will this post & the potential name collisions caused by this change be documented and easily available for years to come? Will new developers who might stumble upon legacy BodyMover objects know about it?