Is your feature request related to a problem? Please describe.
Projects already do it. When you create a new project and proji notices that its already tracking a project at that path, proji will ask you, if you want to replace the project with the new one. Classes don't do that. When you're importing a new package and a tracked package shares the same label (which has to be unique), proji will just fail and tell you, that the label is already taken.

Describe the solution you'd like
Like with projects, packages should ask you for an optional replacement of an existing package when importing a new one.