I just went and popped a blade in to my notched Aristocrat. When the razor is open, there is minuscule movement of the blade, minuscule. With the doors closed and tightened, there is zero movement. My feeling is unless you're a collector who wants the earlier notchless design, this is a Seinfeld subject.
...Seinfeld subject...a post about nothing?
But this is what fanatics of anything do...dissect even the tiniest minutiae of every minor detail of the subject of their obsession.
Sixty years ago, I bet no man ever pondered the blade retention properties of his 50-cent Gillette TTO, or lamented the loss of his "good ol' notched" Superspeed that he left at the hotel and couldn't replace with a new notcher. He may have preferred the notches, but I'm sure he got over it in about three seconds.