Yes however the difference is that ZFS was made closed source by Oracle and then basically the entire ZFS team quit oracle to work on OpenZFS instead. With Has

Yes however the difference is that ZFS was made closed source by Oracle and then basically the entire ZFS team quit oracle to work on OpenZFS instead. With Hashicorp, the project is still "open source" but under a license that makes it potentially dangerous to any competitors. That makes it much harder for a fork to operate without exposing itself to legal risk. For example if any of the code implemented on the fork after the change was too similar to code by Hashicorp that could open the fork devs up to a legal battle. With ZFS that was never a concern since the new changes weren't publicly available on the closed source version and importantly all the brains behind the project promptly quit to work on the open source version instead.