https://mtgrocks.com/wizards-of-the-coa ... ster-pack/
So they realized they screwed up with the MoM:Aftermath and have attempted to fix the issues. Breaking things down a bit, the Beyond Booster contains seven cards and one token/ad. The first three slots for Beyond Boosters are guaranteed to be nonfoil uncommon cards. This is a similar structure to the Epilogue Boosters.
Lucky (or not?) for
@DirkGently you won't be bale to draft the Assassin's creed set
Fortunately, it was also revealed in this week's Weekly MTG that the "total size of a Beyond Booster is about double that of an Epilogue set." This means that about 100 cards will be available in a Beyond Booster set, but there are no common cards in the set.
Slot four contains either a dedicated non-foil land or a scene card. Calling back to the Lord of the Rings: Tales of Middle-earth set, Scene cards are cards that take artwork from a larger scene. You can combine all of the Scene art cards to recreate the scene yourself. These, of course, can also contain rare cards.
Slot five contains the standard Rare or Mythic per pack. Slot six is a guaranteed traditional foil card, and slot #7 contains some sort of Booster fun shenanigans. Reprints and new cards were mentioned to appear in Beyond Boosters.