You misunderstand me I think. Different cover art is currently used as an explicit reason for a new release in the guidelines, so you can ‘officially’ add any digital release with a different cover.
I have added all those releases, and am just asking if people would confused or bothered by them if they didn’t have different cover art. I want them all to be there, even if the only difference was different track titles or format (as long as they are annotated and disambiguated effectively).
For me whether a soundtrack (or a cd) is packaged with another product is irrelevant. If it can be played or ripped someone’s going to want to tag it. And sometimes it’s the only way to get a soundtrack, and we would never say a soundtrack can’t be on here at all afaik. But I appreciate that you might not have any interest if you don’t have those types of files yourself 
The ‘Steam’ example is actually a good example why this is good data for MB to have. Often you have no idea what format you’re getting from a storefront, or how many tracks etc. I have all of those releases and can confirm those track lists are correct even if the Steam tracklist on the site is missing a track - information you can literally not find anywhere else on the internet. And won’t be able to once again if they are merged because someone ‘doesn’t see the need’ for multiple digital releases.