I don’t believe that the market that the DD is aiming for is the people who use CY. If that were so the store would be on 13th or 16is or 18is Ave. By putting it next to the hospital they are going agree employees and visitors who are not from Borough Park.
In any event, no should decide where to eat or not eat based upon who supposedly did or didn’t eat there. They should check the hashgacha.