This is in our backlog, but votes and comments about how you would expect this to work are very helpful to our planning/designing the feature so please keep them coming.
Also, for some scenarios in this space Access Reviews (https://docs.microsoft.com/en-us/azure/active-directory/governance/manage-guest-access-with-access-reviews) can be a good way of removing users who no longer need access, including those who don’t have accounts anymore. (Thanks Shawn for pointing that out for everyone!)
An error occurred while saving the commentJames Mayhair commented
Any direction from the product group would be greatly appreciated.