Apple's App Store licensing agreement allows you to distribute GPL v2 software. However, the GPL v2 license does not allow distribution under Apple's licensing terms.

It's possible to have GPL v2-licensed software on the App Store, but it essentially requires relicensing or dual licensing by the copyright holder (which is what they do here with selling a commercial license to distribute).

VLC was pulled from the App Store due to its license being GPLv2 at the time.