Typically, for an ISR offer, your DS would have submitted his application through the recruiter, and someone in that district would have flagged his application as a potential for ISR. I don't know if every district does this, but most will have a specific interview done by either the NTAG CO or someone that the CO directs to do it.
Assuming the application is submitted as an ISR, then NSTC will review it for accuracy, but in terms of being in front of a board, those ISR records are completely separate from the rest of the CNSB or standard NROTC scholarships. And unless things have changed, the NTAG will be the one to send out any notification of the scholarship.
The Feb 7-11 board has reported out already. Because ISR is a selection made by the NTAG, there isn't an alternate for those. The general governing directive for ISR is the NAVCRUITCOM 1533.4E. They may be up to revision F but I don't think there have been any major differences. I attached a few pages of that instruction, but it's a big file so I trimmed most of it. You can probably find it in its entirety on the web.
And while most on here know this, the entity that owns this application process is Navy Recruiting Command. I am on the other side of the fence as the PNS. But, my sense is that either 1) some NTAGs are better than others at getting the word out and keeping folks informed, or 2) perhaps DS or DD types aren't copying the information correctly and translating to their parents. So, to the degree that I can, I try to wade through the minutiae. But, for the applications, I am just a passenger in the train, not the conductor, not the engineer, and not even the whistle blower.