We had a support ticket open with MS for 5+ months regarding this issue before a senior engineer pointed me to this link https://learn.microsoft.com/en-us/troubleshoot/mem/intune/known-issues#users-are-signed-out-of-managed-ios-office-apps which brought me here.
I was instructed by that same engineer to open a ticket with the Intune team specifically calling out the "known issues" link and this forum and said they would know how to proceed.
The Intune team apparently had no idea it was an issue and kicked the ticket to the Azure group saying it was a login issue and not their problem. The Azure group, deciding it wasn't their issue, just kicked the ticket to the Office app group.
We are seeing the phantom devices in the admin portal for impacted users with the registration date of 1-01-01 @ 12:00am, but do not see wipe requests.