My thinking is....if place is closed up/locked, and Deaf or hearing want to continue meeting outside in a car, the parking lot or on the sidewalk next to the place, I don't personally see a problem; unless there is sign that specifically states "no loitering" in which case the law has regulated the interaction. But if hearing can stay so long as they are not actually preventing the business from closing, Deaf should be able to also, if hearing people don't like the signing, too bad-
Threat of physical violence or "inappropriate behavior" is something else altogether.