There are a plethora of cards with an F regulation, as every V and VStar, every Radiant Pokmon, and a slew of other cards will no longer be legal for standard play
You must also track how each became face down (manifested, cast face down using the morph ability, and so on)
Cards like Budew completely stop the deck from functioning, and it has horrible matchups into decks like Raging Bolt ex and Gardevoir, both of which are dominant meta threats currently
You just get to reap the delicious benefits, which are in your favor, of course
You can tap any three untapped Zombies you control, including ones you havent controlled continuously since the beginning of your most recent turn, to pay the cost of Cryptbreakers second activated ability
Sometimes, like with the specific in-joke of the Charisma Token or the cards for writing on like the Command Duel Use Card, they wouldnt have any reason to do anything with them again to warrant a release