@romin Such possibility was forseen decades ago and dealt with in advance; "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."

- After a theoretical microsoft purchase, it would no longer be the *Free Software* Foundation.
- If the GPLv4 is proprietary, than it's not a valid future version.
- GNU freedom fighters will be lining up to deal with the proprietary hijackers after the invalid license version is legally rejected.