Earlier quoted context omitted.
From the release notes: sendmsg(2), sendto(2), recvfrom(2) and recvmsg(2) are run without KERNEL_LOCK. The lock is being removed, slowly with care, piece by piece.
Also, I think FreeBSD eliminated the giant lock ~10 years ago and maintains similarly good documentation. It’s just a matter of priorities, and SMP scalability/high performance has never been on the top of the OpenBSD list.
I thinks its a greyscale and have always been. Silly things like floppy (that noone uses) on fbsd used to attach with [GIANT LOCKED] for the longest time (if not still) but it doesn't matter. You would not call fbsd still under GL just because 1.44MB floppy drivers don't get any attention. So its not a binary on-or-off on any OS, its a process of unlocking one part at a time, out of hundreds, thousands of small subsystems and drivers without causing races. OpenBSD is most certainly behind, but there is no nice line over which you can say "Ah, now its not GL anymore", since there will be some part somewhere for some arch where you don't care that still retains the lock, and there were parts from day #1 that was completely unlocked on obsd like the syscall getpid() in all its triviality and race-free-ness.