I dunno about plans but I see potential in something like this since the variant grouping could be made automatic if two releases share all recordings between them. I think this could help solve a problem with “too specific” digital releases which really grinds my gears even though I like the current level of precision.
Imagine a situation where you want to add a “purchase for download” link to a digital release and find out that there exist two digital releases already with identical tracklists but both having different barcodes. The store you want to add your url for doesn’t provide barcode info and even the release date shown is the original release year from 1970s. Should you create a new release for this link? If you wanted to add another url for another store with a similar situation, would you add it to this yearless stub or should you play it safe and create yet another release?
If variant groups had url relationships and those could be easily moved between a variant group and its releases, the beforementioned problem wouldn’t exist. A variant group could have a release from which it takes its tracklist (compare to setting a release group cover art) and so it would act like a normal release. This would help taggers who don’t know or care which specific release is the absolutely correct one for their purposes but don’t want to put potentially incorrect info in their files.