How would they collect on such judgments? This new law does completely abrogate foreign sovereign immunity; just makes a narrow exception regarding Saudi Arabia and 9-11.
You can’t make a ‘minor’ exception to international law and treaties without massive consequences.
If we try it in our courts, and we try to collect on Saudi Assets in the US, then we end up in a (larger) trade war with Saudi Arabia. And there would be retribution from many foreign governments. (Such as trying our soldiers in their courts for war crimes or kidnapping our diplomats)
If it’s tried in an agreed-upon international court, then it would have teeth. And then Pandora’s Box is opened forever.