On July 25, Blizzard confirmed the leak. The release of World of Warcraft Wrath of the Lich King Classic is scheduled for September 26th.
The press release includes the following snippet: “In addition, players will be able to purchase additional upgrades, including new cosmetic items and an [instant] level up to level 70 for those who do not yet have a fully developed character.”
Probably, we are talking about the Wrath Pass, which was previously found by dataminers. Opinions about it are divided: WoW Wrath of the Lich King Classic will introduce a battle pass, or it will be a product similar to that presented with The Burning Crusade Classic add-on. Then the Dark Portal Pass went on sale, allowing you to instantly level up the character, and the deluxe edition also offered to get cosmetic items.