You cannot ship features that depend on cgroups v1. You may not ship features that depend on netlink attributes that exist on some distros, not others.
Yes, there are a few exceptions to the Linux kernel's backward compatibility. I've encountered others, but I don't remember which any more. They are quite rare, though.
cgroups v1 might be the most irritating, because it was useful and something a shipped application or service might realistically use.
