(Don’t take the following comments as a “correction”. It’s more my personal interpretation of the distinction between “archived” and “portable”.)
When I create an “archive” of a KiCAD project, I imagine it’s primarily for future reference. That is, at some future time (weeks, years or decades from now) it will probably be opened and viewed but probably not be modified or added to. The archive will probably be opened or viewed on a different computer than where it was created. For an archive I expect all of the footprints and symbols to be “frozen in time”, as they were at the time the archive was created. (Yes, even if there is an error in a symbol or footprint I want to preserve that error.)
The exception would be when the archive becomes the basis for a new project. In that case, I’d like the capability to clone the archived project into a completely new project. At that time I’d probably want to bring all the symbols and footprints up to their most recent revision, and work with the current libraries as I develop the new project. However, I’d like to have an option (on a case-by-case basis) to keep the footprints and symbols at the revision preserved in the archive.
“Portability”, on the other hand, implies that the project information will be transferred to another computer, and modified in the near future. I want the transferred project to open and display as it did on the original computer. Subsequent work should have the option of drawing on the same library files as the original project, if they are accessible; or drawing from the libraries accessible from the new computer. More importantly, the user should be alerted regarding which libraries are being used.