I do not, but it’s more than just that. Assuming that sendmsg was fixed, we’d still need the conditional policy apparmor network rules. Assuming we had fine-grained network mediation to the point of ‘network nfs’ (note, this is not something that fine-grained network mediation phase 1 or phase 2 is meant to specifically address so I’m speaking hypothetically here), we still would only want to have those rules as conditional policy.
Only if there is something like “if file is on nfs then don’t check network stuff and instead only check the file path/inode label” could we get rid of the conditional policy. That would require a path check in sendmsg which is not something seccomp is designed to do and my guess is this sort of check in the LSMs (ie AppArmor, SELinux, Tomoyo) would not be upstreamable. For a more concrete answer, you’d need someone from the kernel team, John or Tyler to comment, but I think considering changing the kernel in this way is largely academic.