Headscarves in the lecture room

During the spring holidays we traditionally make a lecture course for candidate students. It is not the type of work I like most, but it is our duty and we have nowhere to escape.
This year it was particarly awful. There were about 120 candidate students in a lecture room without loudspeakers. We literally shouted, yet our voices could not be heard past the first 3 rows of seats, provided listeners were not talking. But they resumed talking every 10 minutes, and the noise resembled that at an airport.
At the beginning, many parents were in the room escorting their children, and some girls were wearing headscarves. In an hour or two, both the parents and the headscarves disappeared. Several headscarves could be seen later only occasionally during a break, but not in the lecture room. Should this be hailed as a quick integration success?
We have never before seen candidate students with headscarves. In fact, I have repeatedly travelled to Muslim regions (e.g. last year to Dospat) and I have never seen even there a young woman with a headscarf.
So I think these ensheathed young heads are a worrying sign.