OPT is not a law, so it’s least likely for there to be a lawsuit. There might be big companies opposing the move though. If they move through formal rule-making process, they can end it. They can even create delays in approval and create unnecessary hassle.

I’m not discouraging anyone to go back to F1, however. This can be a good option if you’re genuinely interested in research and continue in academia, but might create lots of challenges if you’re looking for OPT once you graduate especially with the current political climate.