Forum Discussion
disabled on premise AD Account - Consequences for M365 Mailbox\OneDrive data
OK, if you disable an AD user which is synced to O365, the O365 user will then be blocked from signing in too.
If you sync an AD account to O365, then move the AD account to an OU which is not synced, the O365 account will be deleted on the next scheduled sync pass. The result of this is that the O365 account will be moved from the Active Users folder to the Deleted Users folder. It will remain recoverable for 30 days, then it will be permanently purged and not recoverable.
So no, neither of these are options for you i'm afraid.
If you sync the disabled users OU, then the O365 user will not be deleted at the next sync, but would of course still be blocked from signing in.
To remove an employee:
In the admin center, go to the Users > Active users page.
Select the box next to the user's name, and then select Reset password
Enter a new password, and then select Reset. (Don't send it to them.)
Select the user's name to go to their properties pane, and on the OneDrive tab, select Initiate sign-out.