I was honestly asking about the intersection of app store code signing and the anti-tivoization clause in 3.0 (I assumed everyone knew that was the major change or 3.0), but I guess I touched a nerve.
Either way, the GPL 3 was designed with signing already being a thing, GPG had been out for 5+ years. And if signing broke the GPL, I imagine Stallman would have been raising a huge fit about it for decades.
or a closed source including a gpl3 Library in its packaging.
both have nothing with the license and are a common FUD argument by people who do not like the implied freedoms of the gpl when arguing for more permissively comercial licenses, so apologize if i wrongly mistook you for the more probable case.