Dear Felix, I’m unsure how you checked for it, but it’s been shipped [0] in the Debian for over a year since 04c0728c [1].
[0] https://packages.debian.org/search?searchon=contents&keywords=zfs-scrub&mode=filename&suite=testing&arch=any [1] https://salsa.debian.org/zfsonlinux-team/zfs/-/commit/04c0728cdb8c2f58aa7958ef72ab41f3d20df26f
