Changing domain effect on intune

Current environment: we have two domains, we sync users from the first one to azure tenant using AAD connect, and devices from the 2nd AD to the same azure tenant.

• Can I manage devices from the second AD using Intune even if the users are synced from the 1st AD?

Target environment: keep only the 1st AD with users and join devices to 1st AD also

• in this case can we keep managing devices using intune since they are already hybid joined to tenant? or should I reset and re-enroll the devices?