Current SNA here: It depends. I will tell you that for sure they are decreasing the amount of aviation slots available each year to both NROTC and USNA due to the backlog for classing up at flight school, so it will be more competitive than it is now. We were told this a couple months ago by CNETC and CNATRA themselves in Pensacola at an all-hands flight school brief.
What you can do right now: get good grades, GPA is probably the biggest factor in selection tbh. Aim high on the ASTB. Like triple 7s to be safe. You can take it at most 3 times, so study a lot if your first go at it isn't good. Junior spring PRT is going to be the one that counts for service selection most likely. Unit CO's rankings also matter, so be a good midshipman. Major Tier matters a bit too but a Tier 3 mid with a stellar GPA (like myself) will almost always beat out a Tier 1 mid with a subpar GPA, so slack off with academics if you're a STEM major.
Biggest things you can do to improve your chances are to do the best you can do. Nuke draft is also a problem (especially for guys), but just do not put subs or nuke SWO anywhere on your selection sheet come senior year. Even putting it at #5 is considered volunteering for nuke.
