Each of the 50 states has a somewhat unique name, and residents of the state therefore have a unique demonym. Use those instead?

If that’s too many names, Colin Woodward has identified 11 culturally-distinct nations in the US. That would actually promote a lot better understanding of why the country is the way it is. I’d be a Yankee.

Changing the collective name demonym Americans would be confusing during the transition, and for what benefit? Is this really a concern for residents of other countries in the Americas? Are Colombianos really scrambling to be called Americans?

Instead, I suggest taking Pres. Sheinbaum’s suggestion, if you want to do something: Call the continent Mexican America. Everybody would know what you mean from context right away. No confusion, no need to get anybody else to play along.