While all the heroes that we see in Overwatch will be making their way to the new game, Blizzard will also be adding a few more heroes to the game when it arrives.
For now, the only new hero that was confirmed and revealed so far is Sojourn. There is still a lot about Sojourn that Blizzard did not reveal but what they did reveal was the fact that she was a captain in the Overwatch organization and has appeared in a few videos in the past.
She has some cybernetic enhancements which would most likely be where her abilities come from although we still do not what it is right now. She is also Canadian which is nice since there will also be a new Toronto map in the game.
Although Overwatch 2 was announced at BlizzCon, no release date was given yet.