These questions are still subject to Good Subjective.
Basically all questions and answers are either Objective or Subjective or a mix of both. And all Subjective stuff is expected to be Good Subjective, or else it's... you know... not good. All of that is true all the time for all questions and answers no matter what comments have or haven't been posted.
Comments get left when people either feel like leaving a reminder in advance (sometimes treated as noise and removed), or when there's been enough trouble and Bad Subjective answers already that a community member (usually a diamond moderator) feels the need to leave a reminder to help people stay in line.
But the comment there is just a reminder of what's already true, the absence of any such comment doesn't mean the expectations go away.
Consider that "No tresspassing" signs get put down where people seem like they might tresspass and need a firm reminder to not. But the absence of such a sign doesn't mean it's OK to tresspass, and tresspass laws are still a thing that apply even if there isn't a sign about it.