OP said "overseas". Generally Canada and Mexico aren't considered "overseas" from the US, since you can drive there. Probably most people would consider South America to be "overseas" from the US, but I think it's more commonly used for routes that involve crossing an ocean: Europe, Asia, Africa, etc.
As much as people are criticizing the proposed changes to this concept in the US, yes, this is true. In many countries that are arguably more free and democratic than the US even, this is not the way citizenship works and the post comes off as uninformed.
While I agree most countries aren’t like this, most countries also weren’t beacons for immigration. I get where OP is coming from. The US didn’t have a smooth transition from “come on all in yall” to “gtfo” so the jarring realities creates sense for the meme, even if it hits the wrong mark.
They can’t without a constitutional amendment. They might still try to argue that the current constitution says something it doesn’t; they might just extrajudicially say “fuck you” to it.
But the only ones talking about it are assholes and - to be clear - not a majority of Americans.