Section 14 of the GPLv3 says:
The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation.
Is the statement that new versions will be similar in spirit legally binding on the FSF? Suppose someone releases software under "GPL 3 or any later version". Then GPL version 4 is published, and they feel that it violates the spirit of GPL 3. "Similar in spirit" seems like a very subjective matter, would they have a cause of action against the FSF?
Given the kinds of freedoms allowed by the GPL, it might be difficult to prove damages even if the new version violates the spirit, so maybe this would be moot.