CynrikDid you perform removal of Exchange from domain - as in uninstall last Exchange from domain or did you just shutdown last VM running Exchange?
Firstly I would open up Synchronization Service Manager on server running AD Connect and in "Operations" tab find 2 tasks:
Name = domain.com - AAD | Task=Delta Import and Delta Sync
and
Name = domain.local | Task= Export
and see if you got any error in those 3. The export errors are most likely errors with missing privileges for acc running as service.
For some explanation: (GUI should look familiar for people coming from FIM/MIM )
Delta Import performs import data from AAD to local metaverse DB,
Delta Sync merges changes between new object and current metaverse DB objects,
Export performs write changes from metaverse to destination AD.
I would suspect something could be wrong with local AD account designated with write permissions and just to be sure would rerun AD Connect Wizard, wait for next sync cycle/delta force and see once again for some errors and post them here.
MS didn't see a change to the way AD Connect does sync - especially for attributes that don't need additional Write-back configuration:
https://docs.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-sync-attributes-synchronized#exchange-online
Looking for some info from Ex team if you there are no errors, cause that could be a funny task to troubleshot on prod..
Regards,
Hubert