Canonical ships ZoL binaries as of April 2016. They claim doing so doesn't violate the GPL since they are shipping it as a module rather than built into the kernel.
No, they're supplied as kernel modules, packaged separately from the kernel. Before Ubuntu 15.10 you could still install it as a DKMS module (such that it compiled on the system it's being installed on). Now they just ship the pre-built .ko's, saving the user compilation time. There are still userland tools to interact with it zpool, zfs etc.
