https://musicbrainz.org/doc/Style/Specific_types_of_releases/Remixes_and_mashups doesn't currently mention the "Remix" release group type. I find it easy to miss this – I actually hadn't added it on one of the RGs used as an example.

Any objections to me adding a sentence like the following just above the list of examples in the "Releases and release groups" section?

In both cases, the release group should have the "Remix" secondary type.