I was fooled because the text appears without comment as to its apocryphal status on the University of Chicago's current Thomas Browne page, and it is still occasionally mentioned uncritically in several modern works discussing Browne. Incidentally, my citation also lists the fragment as deriving from Religio Medici, which is also wrong; it was published in an omnibus with that work under the collective title of Religio Medici.
However, my earlier point about Ancient Egypt being seen as Satanic is not without warrant. In Paradise Lost Milton expresses the common view that the pagan gods were originally demons, which God himself in Exodus 12:12 seems to confirm when he states that he will pass judgment on these gods. As enemies of Yahweh/Israel, Pharaoh and Satan become equivalent. The Jehovah's Witnesses, following this precedent, wrote in the Watch Tower for November 15, 1928 that the pyramids were built by Satan. Moreover, a persistent Arabic tradition holds that Sheddad Ben Ad built the pyramids; that his race was of giants (like those in Genesis); and that God destroyed the Adites for their presumption at rebelling against God (shades of Satan and the Tower of Babel). The point, of course, is that later people applying their own ethnocentric views (here, later religious views) to earlier cultures distort the earlier cultures' beliefs and recreate them in their own image.