What about the idea that came up here at some point that the stdlib could just be a list of curated nimbles, maintained or at least selected by the Nim compiler developers?
<https://forum.nim-lang.org/t/7983> With stdlib being nimbles, we can imagine that a next version of the compiler will remove a package from its stdlib, but the package being a nimble, continuing to use it would be a no op (or close to).