Whenever this subject comes up (frequently) on various threads, it seems to me that everyone has an opinion about the sizers and the size of their bags. As far as I know/ have seen, the sizer has not changed nor have the correct measurements changed.
All carryon bags should be FLUSH with the measurements and NOT HAVE EXPANSIONS of any sort. If your bag is compliant without expanding every compartment with shoes, books, coats, excess whatever, then they would fit in the sizer. Simple. I hardly think labeling a GA trying to enforce correct rules as having a "bad day" or "rude" or "should be reported" settles this issue.