Starting with Battle for Zendikar, Prerelease Events will no longer come with a "seeded" booster. Confirmed by Mark Rosewater on his blog, prerelease boxes will now come with six regular Battle for Zendikar booster packs and a promo rare, which could be any rare or mythic rare from the set.
Director of Magic R & D Aaron Forsythe made the announcement on Twitter and the reactions rolled in.
Confirmed by @maro254 today: Battle for Zendikar prerelease has no color choice/seed booster. Just 6 normal packs + a literal random promo.
— Aaron Forsythe (@mtgaaron) July 28, 2015
@mtgaaron @maro254 Great change, like seeded packs for some formats (mostly those based around guilds/clans/etc) but better w/o for most.
— Victor Jenny (@Grapplingfarang) July 28, 2015
@mtgaaron @maro254 Awesome! Origins did a decent job, but this what I've been hoping for since Theros.
— Spencer Zimmerman (@Spencer_AZ) July 28, 2015
@mtgaaron @maro254 I dislike the totally random promos (even when they were 1 out of 8). Getting a non-cool promo is very bad experince.
— Vojt?ch Kolá? (@XenderCZ) July 28, 2015
— Dr. Jeebus (@Dr_Jeebus) July 28, 2015
@mtgaaron @maro254 I really dislike this change. I felt like Magic: Origins found the sweet spot for this.
— Matthew Watkins (@oraymw) July 28, 2015