That is an incidental and unimportant difference, not the main one. The main difference is that the newer licenses reserve certain rights that affect the use o

That is an incidental and unimportant difference, not the main one. The main difference is that the newer licenses reserve certain rights that affect the use of the software. The GPL does not reserve any rights exclusively to anyone. Incidentally, copyright holders are not themselves bound by their own public licenses, and that's why some entities use the GPL against its spirit to effectively reserve the right to make proprietary derivatives (or to license that exclusive right separately), but that's not at all part of the GPL. That's because the copyright holders no way of binding themselves to the license term (the best option for that is to assign the copyright to another entity that is committed to protecting the universal rights for everyone).