Hello brichardi, Disconnecting an object from the MV object will trigger the action you selected in the "Deprovisioning windows" on your AD MA configuration. So it can done from nothing to delete the object :)
In your case, I will suggest you to use the "Explicit disconnector" option. If you let the simple "Disconnector" state, it can be re-joined to the MV object, depending on the join rule defined in you configuration...
But keeping the account active/inactive without any other automation/monitoring is a bad practice.
The best way to handle that should be to let MIM sync managing the status of the account. For example, based on the start and end date of the contract of your contractor