Thanks for asking on meta for a discussion.
Your edit is pretty minor and I would put the iTunes connect tag back in since that’s the overall “service” that apple offers which makes this on topic here.
My hesitation to reopen is this second question - it needs to be gone or stated as a fact with references so it doesn’t look like there’s a side question that needs to be addressed first.
Second, iOS does not allow 3rd party dynamic libraries, which means, to my understanding, you can't legally combine GPL and non-GPL code in one iOS app
What sort of answer would you be looking to add @d3vid? This seems much more suited for Stack Overflow since we are not at all a place to discuss code level questions and the license that governs code level decisions seems to be far more apt for developers.
I do get that we could have an answer that literally reviews the license / EULA / developer agreement and explains if Apple mentions anything about license directly. From Apple’s perspective, they may not even say anything except insist the developer is responsible for owning and licensing everything they use to sell.