Blizzard explains what makes Overwatch 2 a true sequel

Overwatch 2 is a unique situation, as any content created for the game will also be available to owners of the original Overwatch. This has caused some confusion about Overwatch 2, as some people are thinking its just a simple expansion, rather than a true sequel. In an interview with EDGE, game director Jeff Kaplan explained why their team believes Overwatch 2 is a fully-fledged sequel in every way.

“A sequel is a brand new game, with new gameplay and features as well as an evolution of the game world. Overwatch 2 is clearly a sequel by my definition. We’ve more than doubled the team size from the original game to make Overwatch 2. We’ll be introducing a full suite of new PvP maps to the game – what you would expect from a sequel to any shooter – including multiple new maps for every existing game mode currently in the game, as well as Push. Overwatch 2 is an order of magnitude larger than the original game, and therefore we consider it a sequel."