I don't know if one can draw the October conclusion. Would HR leave the posting up to expire on their own if they know they won't hire anyone? I say that since

I don't know if one can draw the October conclusion. Would HR leave the posting up to expire on their own if they know they won't hire anyone? I say that since they seem to remove them (presumably because they got enough applicants or actually hired someone) before the 30/31 day mark.