This would be true if they listed "alternative store_s_", but what they actually did is add itch.io to their store in a token way once they started the lawsuit in order to say "Look, we have no problem working with other stores". It's a stunt for the lawsuit. Even the Itch founder who signed the deal said they basically found it bemusing and an effort to gain legal leverage without really doing anything else.

It'd be like if Apple took all of the developers who testified against Apple, reduced their commission to 0% in perpetuity, and then asked the judge to throw out their testimony because the complaints were moot.

(That being said, I do think there are conditions where stores would/should allow other stores, and I think those conditions could be more permissive than the Roblox example. Apple should, medium term, resolve the GeForce Now/XCloud objections.)