I don’t see any real issue keeping it, but it is essentially duplicate data, as far as the database is concerned. that isn’t to say it can’t be useful to some.
that said, for remix releases, I’ve recently started crediting the remixer as the release artist. since a lot of remixes I edit aren’t approved by the original artist (and are therefore a bootleg of the original artist), but it is an official release by the remixer.
(edit: a good example of this is The Living Tombstone)
not usually, but there could be exceptions.