Firstly, I’m not sure how familiar you are with the way SE works in terms of moderation but only elected moderators can handle comment flags not the general community.
Regarding the specific comments, the first doesn’t seem too relevant but it does have some relevance so it’s worth keeping around for that reason.
The second (automated on close/flag) and third comments are about the state of the question: whether it should be closed or open. These are relevant to keep around as it gives information for people in the future to read if they are considering changing the questions state.
The fourth comment is perhaps the only one that doesn’t really need to stay around as, if I remember correctly, Alex has already replied to it in a now deleted comment. However, along with the moderator’s edit it perhaps gives some information that the mod felt the questions weren’t dupes and should stay open which is somewhat relevant to stay around.
In any case none of the comments are really black and white as to whether they want deleting or not.
It’s also worth thinking about what flag type did you use to flag the comments? Using the first comment as an example, mods aren’t required to bu subject matter experts. If the comment looks somewhat on topic they’re more likely to leave it around as it does in this case. So if a comment isn’t obviously “no longer needed”, rude or unkind it’s better to use a customs flag to explain why you feel it is no longer needed.