Providing any solid help here is far beyond me, but some things which came to mind...
The ha-machi is, if my memory is correct, a relatively weak spot (and something which is easy to mess up during polishing). So perhaps the "point" of the ha-machi has simply been broken off at some point, and the break then ground to the current shape? or perhaps ground down by one or more overzealous polishings?
Without having measured anything, I've gotten the feeling that blade widths have a decent amount of "natural" variations, so it doesn't seem likely that one could use such as a criteria to determine if a blade has been shortened or not. My impression is rather that such is seen more on general shape and the nakago.
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