Can I recover a deleted AD user from a copy of the domain controller?

First, check whether the deleted object is still present as a tombstone. Even without the Recycle Bin, it may be possible to restore part of the account, including its SID, although many attributes can be missing.

Get-ADObject with the IncludeDeletedObjects parameter can help you look for it. Treat a tombstone restore as a partial recovery, not a guarantee that the password, group memberships, permissions, or application access will all be back as before.

Check your actual backup system too, not just the VM copy. Some application-aware backup tools can read an Active Directory backup and restore individual objects. If you have one, check its recovery procedure and what it preserves before making changes.

For a critical account, this is a good time to get help from someone experienced with AD recovery. Don't connect an old copy of the domain controller to the live network and hope it sorts itself out.

You could start the copied DC in an isolated environment and inspect the old user attributes, then use that information to help rebuild the account. Keep it isolated from the production network. Getting an old DC running safely can be complicated, so this is more of a recovery exercise than a quick copy and paste.

Recreating the account gives it a new SID. That means matching the old username alone won't automatically bring back permissions tied to the original SID. Group memberships and access to data and applications need checking, and don't assume the old password or licenses will carry over.

Enabling the AD Recycle Bin now is still useful for future deletions, but it doesn't turn this earlier deletion into a full Recycle Bin recovery. Check the remaining recovery options for this account separately.