https://www.cbsnews.com/news/new-pope-could-it-be-american-c...
https://www.cbsnews.com/news/new-pope-could-it-be-american-c...
If there's a political motive in not choosing an American pope until now it's that for most of American history it wouldn't have granted them any influence over American politics. If there's a personal motive it's that until recently they felt insulted that America went for almost 200 years before finally electing a Catholic president.
I don't think they had much control over when Francis died.
Anyways, nothing can end America on such a short timescale. Even if Donald Trump's recent decisions will cause the downfall of America's global pseudo-empire we are not anywhere near a point of no return and he could give up on playing "5D chess" and fix this all within a month; some opportunities would be lost which leads to some unrecoverable economic damage but we'd still be largely in the same position as we were six months ago; consequentially, any fears they may have had about appointing an American pope during a period of global American hegemony are still valid.
You should look into the history of choosing a pope, it’s wild.