RFC: Deprecating version specific manifests

Also introduced (or at least mentioned) in SE-0135 are Version-differentiated package tags (e.g. 1.0.0@swift-4.2). Are we considering deprecating this feature as well? Or is the intention for version-specific tags to be an alternative?

For what it's worth, I only recently learned about version-specific tags, having never seen them in the wild. Given the choice between the two, I prefer version-specific manifests, which is primarily motivated by version-specific tags being SemVer-incompatible.

One other point: This deprecation would impact SE-0292, which is currently under review. The endpoint for fetching package release manifests takes a swift-version query parameter. To avoid an immediate revision to the specification, should we take that part out before SE-0292 is accepted?