Oh god it's still importing even after I disabled the import and deleted events.

Okay, so I ended up having to restart my Phabricator instance to get the import to stop, then "Delete Imported Events" seemed to work right even though it took a reasonably long time to complete from the web UI (I feel like it should really be using the bulk operation infrastructure).

But yeah, it is 100% not good to show this:

and then attach a policy of "All Users" to the imported events.

I think it makes more sense to have events inherit their policy from the import that created them (if they are imported events)? i.e. rather than copy policy settings on import, make the policy pull from the import similar to other systems (like how "build target" view policy is pulled from the "build" view policy).

The advantage of this is that if someone actually does set the wrong policy for the initial import, they can quickly fix up the policies on all imported events just by changing the policy on the import itself.

The policies work like you expect them to. This is just like a revision saying "All Users" but not being visible to users who can't see the corresponding repository.

That said, I'm probably going to change how the UI works.