I haven't personally seen it on HN but it has been an issue at least since the beginning of tariffs, and there's significant rules in the original NAFTA agreement to try and curb it. So it's not new, and definitely predates that report.
Here's a NYT article from April about the difficulty in preventing transhipping.
https://www.nytimes.com/2026/04/07/us/politics/tariffs-trade...