Also, a few years ago the FreeBSD people decided to throw away their own ZFS implementation and import the linux one (OpenZFS) because they couldn’t keep up with the development pace.
Nowadays ZFS development is collaborative but in each major freebsd release it’s clearly marked which OpenZFS releases they imported in the FreeBSD codebase.
On FreeBSD I know its always going to work.
That can only happen if you use the unreliable DKMS way of installing it. If you use zfs-linux provided by archzfs it will only allow updating if it's compatible with the kernel, which in linux-lts case is within couple hours of a kernel update.
https://github.com/archzfs/archzfs https://wiki.archlinux.org/title/ZFS#Kernel-specific_package...
It's probably fair to say that trust in Oracle is irrelevant to OpenZFS.
Where Linux does use ZFS: to the best of my knowledge, it's typically OpenZFS – https://news.ycombinator.com/item?id=47407937 is my own use case.