I wonder if this has to do with the fact that there are enemies inside the Scholarium at a certain point, and not too far from where the vendor appears. That said, they don't seem to reappear once the relevant quest is completed. It would be nice if they could designate the zone as safe (which would presumably get rid of the timer) afterwards.
Tideholm is another place like this.
That can happen in any zone, when there are enough players present in the instance, had the 10 second log out timer in Reapers march the other day. Had it for most of the first few weeks in the new chapter zone.