Sounds legit
I went to a pretty affluent and well regarded school out here in phoenix and my experience was that kids at this school were all but walked through the process and in a graduating class of 60 i'd say 55 got into their first choice school, most of them Ivy league. We had a councelor that started hitting you up like week 3 of FRESHMAN year, I knew a dozen students who were only allowed to take tests on yellow paper AND they could not be timed because of "learning disabilities", I know dudes who took ACT & SAT prep classes 4 years straight and then would start taking the SAT "for real" beginning Junior year until they got a score they were happy with (over 1500 in most cases). Who's parents MANDATED, in coordination with the school that X amount of "volunteer" /extra curricular activities be completed. The shyt was a formula, and a very successful formula.
I"m not sure what the process for reviewing all that information is but to say the wealthy don't have a leg up on that entire process is an outright lie (not that you've said that).
On the flip side, i had friends, very smart friends, smarter than a large chunk of the kids at my highschool who attended IB schools in phoenix that didn't have nearly the same help being forced to go to state schools. (Granted they ultimately ended up doing well for themselves)
I'd actually say something much, much more extreme than that. HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
The college process at elite schools pretty much exists to replicate the elite, privileged class of society. There are, of course, exceptions - and those exceptions, as they say, prove the rule. The crudest analysis I can give is admissions offices do little more than rubberstamp and credentialize the children of the wealthy, just as private high schools do. The good and interesting work an admissions office does is often incidental, and usually has more to do with an image the institution wants to project than any higher or noble ideals. We've abided the creation of a system of credentials that keeps the ruling class in place.
I could write pages and pages of fact-based and experience-based analysis of the role wealth plays in admissions, but it'd most likely be a waste of everyone's time. I'll leave it at this for now: parents who pay between 30 and 60 thousand dollars for private high schools are not paying that much money for their kids to go to anything but one of the best schools in the nation. You have to be a real fukkup or a true idiot to be a kid from an educated, wealthy household who attends a good private school and not get into a top tier school.
I can provide a much more detailed breakdown of how the process is skewed, but I'm not sure how high the interest is.