The thing is for singles, remixes are basically expected and often packaged with the original mix. So, you’d often have a situation like:
Single (1 track) in RG 1
Single (3 tracks, inc. 2 remixes) in RG 1
Single (the 2 remixes on their own)
It seems very strange not to put that in RG 1 too.
On the other hand, rap style remixes with the same beat but more vocalists are most commonly released on their own, months after the original song came out, and are (in my experience at least) considered more of a separate thing than normal remixes are. We also create new works for those, but of course that’s kinda required by the new lyricists (remixes do not often get a new work, unless they do get a new composer credit officially which isn’t common)