It is difficult to solve problems when you don't know what you don't know, especially when what you don't know is that you have a problem. Season tickets always sell out in minutes. It is a reasonable assumption for students that these sold out as well and that is the reason they didn't get notified of anything. Based on everything publicly available, it looks like the first report that the student section didn't sell out was Audrey's tweet yesterday.
We know no rejection emails went out, because if they did, Kris Peterson would know they were sent and presumably wouldn't have made the statement.
Kris never made any statements on her official twitter page:
https://x.com/GoPSUKris
Nothing on the official page:
https://x.com/GoPSUsports
Looks like similar situation at Texas.