Today’s random tin foil hat theory that’s probably wrong.
I figured I’d test my theory on what that symbol on page 7 was. I poked an old friend of mine who knows a thing or three about pagan symbols and wiccans and showed it to her. The first words of her mouth were ‘that means winter’.
Given that one of the first page is an arcane symbol or protection circle of some sort, and the last page is this rune I wildly guess that those runes are some sort of protective spell on the book, preventing it from being read. The approach of the winter solsitice in 2 weeks (In the Northern Hemisphere anyway) is one possibility for the reason the pages are beginning to be revealed.
If I guess right (and let’s face it, you don’t want to bet that I am) the book will become more readable approaching the 21st. Whether it becomes less readable after the 21st or remains that way for all of winter I don’t know, but it’d behoove us to keep copies of everything we get our hands on in case it fades away.