>>41609129More than a decade ago TPCI went ballistic on Wizards of the Coast because one of their employees leaked a card list of a upcoming TGC set, and it started the fight that eventually led to Hasbro completely losing contact with them and the Pokemon toy license.
If they take something as measly as cards seriously, you can bet they will investigate leaks of the Guide's sort too. Specially since the Guide's publisher is themselves, meaning that the leak's source could've been one of their own people.