I know this has been answered and I tried a thread search, but: do the school rankings for NROTC matter anymore in terms of being strategic in case a number 2-5 choice unit fills up?
The answer is no. Units do not 'fill up' anymore. The applicant will still list a #1-5 on the application, but upon receipt of the scholarship it will be placed at the #1 school. If you change your mind, send an email (pnsc_nrotc.placement@navy.mil). And to be clear, you can move your scholarship to any school with an NROTC program (assuming you were granted admission), regardless of whether that school is listed in your top 5 choices.
This past summer, NSTC placed a brief hold on scholarship placement changes. NSI was the reason. The unit where your scholarship was placed was responsible for handling NSI paperwork. They needed to put a hold on processing change requests to avoid shifting paperwork as NSI got closer. Hope that makes sense.