While they werent playable and did not provide any benefits to players, you could display them as decoration
Id also argue this rule already has changed, as it did with the rewording of rule 11 after the release of Ikoria to make room for the introduction of the Companion mechanic
This set booster box contains 30 packs of 12 cards each, and every pack has at least one multiverse legend card, one card of rarity Rare or higher, and one foil card
Pick Showcase if you want a themed, premium treatment (Box Topper and Mystical Archives live here)
If anything, the promise of future Marvel Commander decks may just help in dispelling any lingering doubts that Marvel precons were never coming
Historic was the format of choice, one that is completely Arena-centric