Office 365 Environment, SharePoint Online, Responsive Form (not able to change to New Responsive Form at this time).

I've got a form that has a SharePoint Lookup field. This field looks up the Locations (aprox. 80-100 different locations). Once a month this list is updated and some close. The lookup field is set to look up the view Active Branches, on the Branch List, so only the ones listed as NOT closed will show.

The problem is that Microsoft has that auto fill/populate forms and when someone chooses a location, it is remember for the next time. So when the location closes and is no longer an option in the drop down menu, it is still there from the last time the form was filled out and the user can choose that option. 

How do I (without going to all 5,500 employees individually) make it so that the field looks at the list to confirm that it is on the specified Lookup view?