[crazygringo]

If you owe money to the IRS, you need to file a tax return whether you're a US citizen or not.

Now you might say, well what is the US gonna do if you don't?

Well, the people mentioned in the article receive Social Security (so "no ties to the US at all" is false), and you can 100% expect their SS checks to be garnished to cover debt to the IRS, as this happens all the time with unpaid back taxes.

So it's not going to be any free money at the end of the day.

The whole process would obviously take a few years, but literally all the systems are already in place for it. Nothing special even needs to be done. It'll just happen.