No, once they pass Battle Stations and are "capped" there is nothing that can set back thier graduation date. They may miss their PIR due to some catastrophe, but will ship out as soon as they recover.
The PIR for Thanksgiving week will be on Wednesday, 22 November. The Graduation the week of Veterans Day is on Thursday, 9 November
I posted this on the PIR Group page for 11/22 from the RTC website:
This is a Wednesday graduation due to the Thanksgiving Holiday
Dates and Times to pick up your Tickets for PIR (as per RTC website):