The license issue in the very worst case (but even that is quite questionable and I would say that Linus is a bit paranoid here) could only be a problem for a d

The license issue in the very worst case (but even that is quite questionable and I would say that Linus is a bit paranoid here) could only be a problem for a distro that ships it by default, you as the end user can freely use both linux and ZFS, as well as their combination.