I've learned the yield for the service academies is very high. In other words, the vast majority of appointments are accepted.
So, odds are long - not impossible - just long.
If you plan to stay on the waitlist, my recommendation is to lock in plan B. Pay the deposits if required by Plan B school. Stay in USNA report-day shape, and wait for the call forward. If it doesn't come - then drive relentlessly to your goal(s) at Plan B school. Reapply next year if you want - application is open for business, I believe.
Congrats to all on the waitlist - quite an accomplishment - don't let anyone tell you it isn't.