OSTechNixUbuntu 26.10 plans to strip ZFS, Btrfs, LVM, and LUKS encryption from the signed GRUB bootloader to improve security.
Full details here: https://ostechnix.com/ubuntu-26-10-may-drop-zfs-lvm-and-luks-support-from-grub/
Udo B.@ostechnix ZFS integration was the very last reason (for me) to use Ubuntu... :-(