They should, and are expected to. If they do not know them, they are likely to be sent home. I would say that well over 90% of them do. That has nothing to do with the Zero day.
As far as new hires, I would guess that the new hires now are MUCH better than in past years as a whole. I can not imagine that there has been more experience in new hire classes at any point in PSA's history. More than half of the classes are prior 121, and another 25% at least are prior military. Out of a class of 30, about 8 of them are 1500 hour guys (and some of those were part 135 cargo pilots).
It is not uncommon for new hires now to have 5,000 hours in the CRJ. There are usually a few prior 121 Captains in each class as well. If you were to average the turbine-only time in the new hire class, I bet it would be well over 2000 hours per student.
It may be true that the expectations for new hires now are much higher than they were in the past, thus the additional class time. That is another theory.