Will this somehow liberate ZFS?

It could make it worse. IP from companies that got chopped up and sold for parts can be a nightmare. You may have to do deals with multiple parties, and it can be unclear who owns what (even to the potential owners themselves).

It’ll just make their auditors and legal team desperate for money, which is kinda horrifying to consider.

How does ZFS need to be liberated?

There is debate as to whether the FreeZFS license (CDDL) is compatible with the GPL, which is why FreeZFS is not part of the Linux Kernel. Some distros are baking it in, but there has long been concern about if merging it violates the license or not.

They took the entire Solaris code back to proprietary source and kept improving ZFS themselves. For instance, they added encryption.

Even if Oracle evaporated and their contemporary ZFS source became unencumbered, I doubt OpenZFS would want to try and merge significantly parts. They already have their own encryption implementation for example.

> They took the entire Solaris code back to proprietary source and kept improving ZFS themselves.

And OpenZFS/Linux/FreeBSD kept improving ZFS as well.

> For instance, they added encryption.

As did OpenZFS.