I have had this suspicion backed up for me from a source that wishes to remain undisclosed, so it isnt just idle conjecture on my part
I've experimented with other tools, including a swivel-blade knife, glue, and fake gems, but I have come back to my base set
Dance with Calamity Exxaxl: I like how this card is going to show exactly how much restraint you have, since you may exile the top card of your library as many times as you choose
But its also got a lot of timing things that are fun
The answer is that you are guaranteed to open not only four rares / mythics each pack but also four special printings, with each collector booster pack offering one foil-etched rare or mythic, one alt-frame rare or mythic, one sketch or borderless rare or mythic, and one extended-art rare