I've never liked this idea. What's to keep the FSF from adding a "you give us royalty-free rights to all your patents for eternity" as a clause in GPL v4?
The author is never forced to use a later version. "Version 2 of the GPL or any later version" simply means that distributor (other than the author) can choose between using gplv2, gplv3, gplv4 and so on.
The author is always free pick any license of their choosing for work that they have themselves has authored.
The author is always free pick any license of their choosing for work that they have themselves has authored.