It doesn’t appear to have changed recently, but I would agree with you it doesn’t make sense.
With some hypothetical Connicks I’d expect the sort order to be:
George Connick
Harry Connick, Jr.
Harry Connick, Sr.
Isabel Connick
Ralph Connick, Jr.
Ralph Connick, Sr.
…but if sorted according to the guideline as written, we would get
Harry Connick, Jr.
Ralph Connick, Jr.
Harry Connick, Sr.
Ralph Connick, Sr.
George Connick
Isabel Connick
(I think that’s where George and Isabel would end up - the space in “Connick Sr., Ralph” would sort ahead of the comma in “Connick, George”)