I wouldn't think so. They are fairly relaxed about parents coming to watch the PRT before Plebe Parents Weekend (roughly 6 weeks after I-Day), but I would think that they might resist the idea of parents showing up to Plebe-spot, only 2 days after I-Day.
With that said, if you are there on the yard and you happen to be sitting in the bleachers drinking coffee (before they get there) and just happen to see them doing their morning PEP workout, then no harm no foul, right? It's even money if they ask you to leave.
If you walk in that unGodly early, be prepared for a strange look or two and to answer some questions at the gate, like "what is your reason for visiting this morning"?
I think my DS said that they were up at 0500 and on the field by 0530, during PS.