The release artist is Various Artists because the releases were merged using the "Merge Releases (Various Artists)" edit type (which, for historical reasons, used to automatically set the release artist to Various Artists) - http://classic.musicbrainz.org/show/edit/?editid=5808192 It seems this information is no longer shown though.

The releases which were merged into that one are not shown in the edit history because of the pre-NGS edit system and we don't (I imagine) have enough information available to be able to do anything about it. It's really only a guess, but http://beta.musicbrainz.org/edit/2412999 looks like it was probably the release that got merged into the one you linked.

I'm thinking the fix for this may simply be to say "Merge releases (Various Artists)" for these type of edits. Then at least it's clear that's a semantically different sort of edit.

Presuming comments get responded to on codereview, this should be in the 09-03 release.