It looks like Overwatch 2 might soon drop the number from its name
Last March, Overwatch lead Aaron Keller expressed a desire for players to refer to the game simply as "Overwatch," without the "2." While no explicit changes have been made since then, recent signs suggest Blizzard might indeed be moving in that direction.
For instance, on Steam, the story mission pack "Invasion" is now called the "Overwatch — Invasion Bundle" — without the number "2." Furthermore, in the announcement for the upcoming "Blizzard Showcase" broadcast, the game is also referred to simply as "Overwatch."
We might hear official news on this matter as early as the evening of February 4th during the special "Overwatch Deep Dive" stream.