I went to college in the Bay Area and to a small private college with significant portion of very wealthy. Some in the private college concealed their wealth, some didn't. The thing is, most middle or above folks with an once of sophistication can sense the trust fund kid a mile away - most working class can sense something too, just maybe don't know the middle-class from the trust funders. I'm shocked the author was shocked to discover someone, at
Yale, who spent their time in self-absorbed, non-survival-oriented activity was very wealthy. I guess some at the Ivy League spend their time learning to act wealthy without realizing that's what they're doing (I think the 2% of actually poor who get into the Ivy Leagues tend to be "hard working rules followers", who by this tend to not notice the obvious about people).
But given the real wealthy folks signal who they are, whether they like it or not, all day long, the situation makes your point about "they have to conceal it to be treated as human" ring totally false. Nah, they can't conceal it, not to very many, and most know it.
I've met some who didn't know but they were sad and I assume there are others who go in for much deeper cover but that's a small minority.