Commissioning, at least for AFROTC, is done cadet by cadet. It is not 30 mids standing up and taking the oath at the same time. At this time it would not be set for their private ceremony.
There are limited officers who can swear them in. Additionally due to the size of PSU, they will impact who goes when.
For example PSU Poli Sci may confer the degree on their school at 10, thus, ROTC will make sure that they will not commission anyone at that time. Engineering may say 11, and Business is at 11 too. Somebody will have to move for commissioning.
FWIW, to be asked to attend a commissioning, is considered an honor to the guest. It is not willy nilly. I don't know if you]re an aunt or uncle, and if it is your sister or brother's child. I will say our DS in 15 months will be commissioned, and I can tell you that on that day, as he is pinned on I will be in tears.
Just so you know, at this ceremony, they ask for specific people to pin on those bars. They get up in front of everyone and place the bars on their shoulders. It is highly emotional. My bet is your sibling will be pinning him on. That was their little boy who is now a man, in one fell swoop
It is also highly emotional to hear them say at @22 I swear/affirm to uphold the Constitution...
It is the most amazing thing you will ever experience in your life...minus their retirement ceremony