Starting on August 31, 2018, Wizards of the Coast will no longer be fulfilling direct orders to their Wizards Play Network (WPN) retailers. This ends a program that was started back in 1999 and will direct retailers to distribution channels for product releases. Not only will Magic the Gathering be affected, but Dungeons & Dragons and other existing and upcoming properties sold by Wizards of the Coast.
You can read more about it on the WPN website here: https://wpn.wizards.com/en/article/us-canada-wizards-direct-sales-ends-831