You make a valid point about putting Maya Angelou on the quarter as essentially an empty gesture. I'm reminded of having seen Shirley Chisholm at the '72 DNC. There was talk, talk, talk about how courageous & inspiring she was by pols & operatives who never offered her any real party support for her candidacy.
So, I get that. But I'm not certain why you're bringing Washington into this. Sure, he'll always be a slave owner & "destroyer of black dreams," but he also always be the leader who successfully pursued the war of independence & set a precedent of presidential limitation & deference to the Constitution.
Wrt what future Americans learn, I dunno. I went to school during the Cold War reciting the Pledge of Allegiance every am. Compulsory patriotism. Yet I think my generation was well aware that Washington was a slave owner. And so be it. I guess it's up to the individual to determine what those facts in juxtaposition amount to.
I do think Angelou & Washington on the same coin rather elegantly depict the paradoxes & contradictions of this republic & its history.