It is not enforced unless somebody insists, but the AppStore has never been compatible with the GPL. We choose MPL 2.0 in part because of these restrictions. Basically the same thing, but it does also include some branding / trademark protections, which a while back Damus had issues with as well.

https://www.fsf.org/news/2010-05-app-store-compliance

https://www.engadget.com/2011-01-09-the-gpl-the-app-store-and-you.html