Elastic promises "open"—delivers proprietary

> He goes on to remind developers that signing a CLA sets up this kind of loophole

> unless all of the previous contributors (including Elastic) sign a new agreement, AWS would be unable to relicense the code anyway

This is wrong as far as I can tell. In this article, relicense seems to refer to the common loose definition of changing the effective license for future releases, and that is perfectly able to be done without any CLA for lax pushover licenses like this case with Apache v2. Just write the new code under a proprietary license which "subsumes" the lax license, see https://www.gnu.org/licenses/license-compatibility.en.html . This is a common practice in proprietary software and one of the biggest reasons to use copyleft licenses.