@aglages - While I don’t personally know of anyone that this is happened to, it’s not beyond imagination that this would happen. Congress members are only allowed to have 5 midshipmen under their nomination at the naval academy at any one time, and I think they have a limit to how many nominations they can give out per year.
Some investigation reveals that the prep school is primarily for students who are borderline for the academies and could be improved in a year, and especially for racial/ethnic minorities and students from low SES backgrounds who aren’t competitive for admission but could be improved. About 1/3 of the NAPS class are recruited athletes, and it seems that significant proportions of the best athletes at the academies came in through prep school (see this article: http://www.washingtonpost.com/blogs/college-inc/post/naval-academy-prep-school-asset-or-liability/2011/10/19/gIQAlDLPyL_blog.html). In any case, none of these things makes the academies differ much from elite universities. Many elite universities offer deferred admission to recruited athletes (or development admits or legacies) to give them a semester or year to improve before beginning (they just don’t have a formal program for it). And a lot of top universities have formal summer programs for pre-freshman, largely URMs and low-income students, who need extra prep before they can begin.
My thing is that I’m not really sure why that’s a bad thing. The goal is to take the best and the brightest, not just those who have the luck to have been born in favorable conditions to manifest their brilliance. If you can take a group of borderline candidates and in a year of prep school turn 60% of them into someone competitive for the naval academy (which is what NAPS does), then…I think that’s success!