This is an interesting topic: be free to comment on anything VS respect authors' wishes to decide where this discussion should happening.
It's not an easy choice for me.
No, highlighter should not be disabled, since they create a new note. In fact if you want to actually comment something you can still do it, simply quoting the event. No free-speech is harmed here.
The point is to let the author to "shape" their home; it's no small thing.
Of course, there may still be clients that ignore this tag and allow comments, and naturally display any comments that may exist.
