Hearthstone's Classic format will be arriving in 2021. BlizzConline, this year's version of BlizzCon, is currently ongoing, and Hearthstone is one of many games that for which major updates were announced.
Hearthstone Classic Format Arrives in 2021
For Hearthstone's Year of the Gryphon, major changes are coming to the game, and one of the most anticipated changes is the coming of a "classic format." This new mode will allow players to play the game as it originally was when it launched in 2014. Players will compete with the original 240 cards from launch, just as they were in 2014. All balance changes those cards may have had since they were released are being reverted, but cosmetic changes to those cards will remain. The classic format will also include classic rewards and classic cosmetics.
Blizzard also announced a new core set coming to the Standard format reimagining 3 legendary dragons cards. It looks as if the new Hearthstone year will have many callbacks to times past.
Classic format is expected to launch later this year with the patch for Hearthstone's next expansion.