I've seen relatively little discussion about these lawsuits, but I do think there is a pretty good chance that SCOTUS will rule these tariffs unconstitutional. (It's certainly more likely than Congress rescinding the powers they've ceded to the presidency.)

Constitutionally, the power to set tariffs resides with the Legislative branch, not the Executive branch. Congress has delegated some authority to set tariffs under certain conditions (namely, emergencies and matters related to national security). But the Court is clear that one branch cannot delegate all of its powers to another. The Court is pretty deferential to the Executive branch, especially in matters of national security. But no matter how much you squint, it's hard to see how setting broad based tariffs on all goods from every foreign countries qualifies under the Emergency Economic Powers Act.