If you are referring to the VPP Invitation sidebar item where you view the usage and it shows the invitations that were sent out, you are not removing them from App distribution. You are simply removing the "extra" invitations that may have been sent out (if there are multiple).
are you looking to reclaim the licenses that you scoped to those users?
I am wondering about this as well. I started out with small invitations so they can add up - if I want to clean them and delete them the user record no longer has an Associated Invitation. What I have not tested is - does this trigger app uninstalls?
I thought I had tested this on my test server but cannot find my results. Will find time to test next week if no one else jumps in.
IIRC, you have to remove the user from the directory group that the VPP scope covers. Once they are removed from the group, and the JSS reads that the user is no longer in the group in directory services, it will remove the app from their account. Then you can reassign the app as needed. I don't remember the specific process, but I am waiting for a "revoke app" button to be implemented in the JSS. That's my big feature request.
I did some testing.
Deleting an invitation does NOT affect users who have already agreed to Accept the Invitation. The agreement associates the user to your organization, and the JSS populates the vpp_user_accounts table with the itunes_store_account_hash for the user.
Deleting the invitation does clear entries from the vpp_invitation_usage table, including the various statuses of 'Sent', 'Clicked Link', and 'Associated'.
I have created a feature request asking for the ability to know the Associated status even after the Invitation has been deleted. https://jamfnation.jamfsoftware.com/featureRequest.html?id=2741
In further testing, I also determined that if I wanted to revoke a VPP license from a user, I need them out of scope for the VPP Assignment. There is a feature request discussing this here. https://jamfnation.jamfsoftware.com/featureRequest.html?id=2530