Hey Paul,
We are trying to repro this in an internal environment but it is complex. Basically I am just at the point where I am trying to determine if there is an issue with our environment, a bug, or if it is working as designed. Unfortunately, I can't seem to determine
how it is supposed to work because the documentation seems to conflict itself. I originally read the links you provided and that is where I had the same opinion, PWA wont inactivate only reactivate. But, then a colleague found this:
https://docs.microsoft.com/en-us/project/deactivate-user-accounts-in-project-server
"When you are using Active Directory synchronization, Project Web App users not found in the Active Directory group being synchronized
will be deactivated."
The document says it applies to Project Server 2016, but I am wondering if maybe this document is old and wasn't updated fully? Since I know that in the past (2007?) there was a time where it did inactivate
resources?