Not really a problem for users. Only for people who want to redistribute a fork. It matters if you are Apple or Sony, but not for most people.
incidentally, the requirement of the GPL is not to upstream your stuff, but to offer to make the modified source available to anyone you distribute the code to. Often the same in practice, but does not have to be.
incidentally, the requirement of the GPL is not to upstream your stuff, but to offer to make the modified source available to anyone you distribute the code to. Often the same in practice, but does not have to be.