They could have an exhibit like that, perhaps describing how they were trying to make amends, donating money to projects promoting pluralism and diversity, opposing authoritarianism around the world, helping the descendants of those they harmed, etc.
But they're not going to, because the people in charge don't sincerely care about the topic.
As for Iraq: I don't see much evidence that US actions there were "best-intentioned", or even well-intentioned.
Imperial hubris. Surely the US can simply decide to own the oil and poppy fields with no consequences, right?
It's not like people aren't still frothing at the mouth to repeat the same mistake in Venezuela or Palestine or Yemen. Maintaining empire requires shows of force. There's always profit to be made along the way. It motivates itself
But they're not going to, because the people in charge don't sincerely care about the topic.
As for Iraq: I don't see much evidence that US actions there were "best-intentioned", or even well-intentioned.