Apple has threatened to remove Amphetamine from the App Store

Might as well call it Poison Pill. What a waste of energy on Apple's part and a perfect grounds for a lawsuit. Apple approved this app with no problems and all of a sudden there is a problem where nothing has changed. Take them to court and dispute it. I assure you they will not be able to prove that this app violates the contract that was agreed to.

What I see here as complacency on peoples' part here is ridiculous. Companies and people never stop until they are tested. Apple would have never made a small business contract for the app store had it not been for Epic's lawsuit.

There even a comment below where Apple had no issues featuring the app: https://apps.apple.com/us/story/id1470456860

This is winnable in court. Settle for Apple paying for the cost of re-brand and lawyers if they do not want to continue the dispute in court.

It is almost a certainty that the Apple's ToS mandates arbitration instead of a real court and definitely allows them to remove an app at any time for any reason. There is no reason for Apple to not CTA in their ToS since developers have no where else to go.

What exactly is the dev supposed to sue for..?

Apple has full control of their platform and can make any arbitrary calls. If they wanted to censor all pg-13 material tomorrow, they could (though they would face consumer backlash).

One recent exception might be anti-competitive behaviors, but I don't think that applies here.

I think it's just hard learning that when you build your business entirely on a platform or via another business, you are at the mercy of their whims unless you have the resources to extract yourself.