I spun up a VM with Ubuntu 16.04, updated, created a zpool on a second disk, booted a Ubuntu 20 ISO, and was able to import the pool without issue, just a warning saying it needed to be upgraded.
This Monday, ZFS on Linux lead developer Brian Behlendorf published the OpenZFS 2.0.0 release to GitHub. Along with quite a lot of new features, the announcement brings an end to the former ...