- Standard format. Rampaging Ferocidon is unbanned.
- Modern format. Hogaak, Arisen Necropolis and Faithless Looting are banned. Stonefore Mystic is unbanned.
- Vintage format. Karn, the Great Creator, Mystic Forge, Mental Misstep, Golgari Grave-Troll are all restricted. Fastbond is unrestricted.
Hogaak was the first truly format-warping card to come out of an in-print retail set since Aetherworks Marvel in Kaladesh. WOTC has been making an active effort to make sure cards that irreparably alter the tournament metagame aren't printed in newer sets because packs with banned cards are a hard sell to players, but it was clear that Hogaak slipped through the cracks. Thus, the "Summer of Hogaak", as Modern players had referred to it, came to a close this morning.
Up until this announcement, Modern Horizons was over-performing in sales according to the Hasbro Q2 Report (see "'Magic' Sales Drive Hasbro Q2 Growth").