of the two events you mention, the Coachella tent is not a platinum card event, rather it's an Amex value add if you purchase tickets through Amex's portal - they have an exclusive deal with the festival, and also have one with Panorama in NYC, and some other festivals.

The Hamilton wasn't a platinum card event, it was an Amex Ambassador event. There for visibility, i.e., social media influencers for the most part.