Apple uses no Turing complete policy. So you also can't bundle a python or ruby interpreter in iOS.
Its still anti-competitive but in a different area which is language and api. They are basically trying to push devs to use their native OS apis.
PWA are also screwed up in Safari for a reason.
That’s surely absurdly difficult to test, and provably impossible to prove the negative (i.e. my app is not Turing complete.) Is a calculator app not Turing complete? What about Google Sheets?
That's unlikely, Kivy is also used for commercial apps. Bundling interpreters is allowed, but you must not use them to execute arbitrary code, unless you do it for educational purposes. Kivy doesn't load remote code, so it's not affected by this policy.