Why does the the Github app automatically unsubscribe when the user who set up the subscription revokes GH access?

[nick-catalist]

Let me be more specific --

I am wondering whether this is just a courtesy for security purposes -- i.e. it's being conservative in terms of having hanging subscriptions, and so wants a new user to actively subscribe to the channel again to continue getting notifications.

OR is this a functionality thing? Is the GH app no longer able to access the subscription because under the hood somewhere it is using the auth of the user who subscribed to get events on a given repo?

I assume it's the first. My understanding is that the Slack app, once installed on Github, now has its own permissions and app/installation tokens. So, it should not be relying on a given user for any subscriptions to a given repo. But the fact that it auto unsubscribes when the user who originally set up the subscription leaves/revokes permissions makes me question this.

What's actually happening?