As someone who has been a member of HN, longer than most I would say you should not apply that rule too broadly. Unless I am missing something, he just said "I'm probably gonna get down voted.". There is nothing wrong with that. People say that all the time on HN. [1]

That guideline talks about the case when someone explicitly complains about getting downvoted after the fact. Even comments that say "I don't know why I have been downvoted" are okay imho. Everyone should be allowed to ask why they are being down voted.

[1] As a site note: Usually types of comments actually get up voted. HN rarely down votes for unpopular opinions if they are well founded.

EDIT: See if you don't believe me:

https://hn.algolia.com/?q=I+am+probably+going+to+get+downvot...

You can try other variations of that phrase as well.