Odd that there's no mention of Annex K support under the "Security/hardening comparison" heading. While it's optional to implement, it certainly applies.
I don't think there's much value in adding an Annex K comparison anywhere since none of the compared libcs have Annex K functions; comparison items are only meaningful where they differ. Even if some libcs did have it, though, I'd be hesitant to put it under hardening. My concept of "hardening" is providing additional properties beyond the scope of the specification (usually this means in places where undefined behavior occurs, but it could also be implementation-defined things, such as using an alternate pointer representation that allows as much bounds-checking as C makes possible).
The general feeling among many implementors seems to be that the Annex K functions are very much the wrong way to harden string/memory handling. I don't know of any linux or bsd libc that has adopted them.