So if one were to assume that the Book’s inclusion is more than just a simple Easter Egg, that would mean that all of Hollywood’s Mummy movies exist in the same continuity.
Kurtzman also confirmed to CinemaBlend’s own Eric Eisenberg and Conner Schwerdtfeger that The Mummy reboot is in continuity with the Boris Karloff-led 1932 movie.
Even without a Brendan Fraser cameo, including the Book of Amun-Ra in The Mummy reboot served not just as a fun tie-in to the previous Mummy franchise, but also seemed to directly connect both series together.
In other words, Earth has been plagued by a lot of undead, bandage-loving monsters in this world.