You're right, though it's effectively a ban on the iPhone because the only way to get apps is through the Apple Store; but yes, it's not like the app itself will stop working, or there will be some IP block, by order of Congress.

Could TikTok work through a browser? I can get to Facebook and YouTube through my iPhone Safari browser. Indeed I buy Kindle ebooks through the iPhone Safari because the Kindle and Amazon apps won't let me make purchases.