Most likely, yes. The entire iOS GPL ban to my understanding only exists due to a combination of an iOS App Store policy that's weirdly enforced (who is surprised...) and the fact that Apple's own code signer is required to be able to distribute an iOS app, and that one is proprietary because Apple, which means you can't use other people's GPL libraries in your apps.
It's highly likely that apps will still required to be signed by Apple, even if distributed outside the Apple App Store, just like Gatekeeper on the Mac.
I don't think the license matters at all, but you may not be able to upload something you can't prove ownership of, and there is still the notary requirement to run, it only changes the distribution channel after all.
What you could maybe do is do reproducible builds, staple the notarised x509 on it afterwards. Then you can 'prove' it is the same app, but still have the signed version in distribution.
