I like this pitch a lot. It is a core idea that I planned to incorporate into an operating system orientated around Swift (SwiftOS, a proposal).
However, I don't think the pitch's implementation is the one we want. I was more aligned with how products already work with the SwiftPM (.static and .dynamic), so developers can choose which linking strategy they want to support/use on a case-by-case basis. Some patching would be necessary (or not?) to fully incorporate the correct usage of dynamic products, which is noted in your other post, but I see it as a net-positive and an absolute necessity.
It is worth noting that I haven't experimented/tested with dynamic linking yet, so my opinion might change on whether or not the existing SwiftPM system should be used (and patched if necessary) instead of adding a new one, but I don't think it will.