I had considered that
@Boycie83 but it's the tiniest of a thin strip. I gather it's for these reasons that the bakelite razors were made. Look also at the Korean wartime superspeed with the plastic tip. Presumably the GEM Bullet Tip (in plastic) was a similar effort.
Ah, so
@TobyC @Bogeyman it might be like Valet razors and how the FEATHER FHS is so cut out it can fit into all variants yet still located and hold in place on the myriad of pin variants:
https://www.theshavingroom.co.uk/community/index.php?threads/valet-feather-compatibility.30834/
Due to very slight iterations in the blade cutouts, the short pin and the bias pin are
guaranteed to fit absolutely all variants of Glaisman's designs (figures 9-16 in the patent above). I can see above that the long slot (of the US-style New) and the twin pin (of the British New) would not fit a number of those blades above. That said, the blade shown in the second part of that patent, which bears a striking if not identical appearance to the modern DE blade, is a compromise (a universal design) to accept all variants of razor.
I can see the reason for the design now, but I still wonder why given that by the time these razors with the short/bias pins came into production, the New blade had been superceded by this universal blade design ... circa 1933? 1934? The standardised Gillette Blue blade.
Maybe the short pin and bias pin are earlier in design than even the long slot or the twin pin, then? Earlier in design yet not produced until later.
... back to
@TobyC's "there is no normal at Gillette". Maybe at the time there was a literal confusion of blades, particularly across markets and at a point where folks were travelling extensively across the world (during those wartime years, Americans, Canadians, Australians, New Zealanders to Europe, North Africa and the Far East; and Europeans), bringing razors and blades, leaving behind blades; these short pin and bias pin models would have been able to accept a much wider variety of blades that might well have been segregated to specific markets otherwise.
I get a general feeling that these short pin and bias pin razors were Service Kit later into the war years.