If copyright was owned, it would never expire - rather it is held, expiring after a set number of years.
When it comes to copyright allocations for GNU projects, whether or not a copyright assignment to the FSF for contributions is required is up to the individual packages maintainers.
The way the assignment works is that the FSF is only given permission to relicense to free licenses for the purpose on furthering free software - they have no legal permission to re-license to a proprietary license, or even to a weak license like MIT expat without a good reason as to why doing so will further free software.
Even assuming that somehow proprietary relicensing goes ahead, most (all?) GNU packages have other copyright holders than the FSF and such freedom enjoyers will not hesitate to enforce their license (usually the GPLv3) against any attempt to turn derivative works of their free software proprietary.
As for the illegality part in the USA - reportably the FBI doesn't agree with you that fake drawings are the same as pizza, as they expressly note not to report drawings in the pizza report form for some reason (working out why is up to you).