Morten St George Theory

[-JKP-]

Logically, your argument can be extended anytime all the way up to the modern day. Anyone at any point after 1597 could have learnt old handwriting, decided to create the marginalia around the Nostradamus quartet, sourced ancient vellum, etc.
If we extend the logic (including the motive for why based upon the provenance and history of the manuscript as established by Rene Z.), then we end up with Rich SantaColuma's "Voynich faked it for cash in the modern era" theory.

I was thinking the same thing, David.

As soon as someone uses the argument that the VMS mimics old styles of handwriting and that it was written on vellum that had been sitting around for two centuries, it pretty much opens to the door to saying it was created any time up to the present day (and not specifically in 1600).