[Update #2]: I'm afraid the update was extremely uneventful. All that happened was that McCree was renamed to Cole Cassidy. There was no event, no story, and no in-game explanation as many had hoped for.
[Update]: Overwatch has added a brand new deathmatch map onto the test servers - Malevento.
As you're most likely heard by this point, Blizzard was recently hit by a massive sexual harassment lawsuit. The lawsuit specifically called out many high ranking employees, and with the evidence against them being quite damning a good chunk of them have already been let go from the company.
Among these people was Diablo 4's lead designer and Blizzard veteran Jesse McCree, which as you might imagine, has created an extremely awkward situation for the Overwatch team. So in order to distance themselves from this whole mess, as well as offer a bit of solidarity to the victims, Overwatch will be changing McCree's name in the next big update.
"We realize that any change to such a well-loved and central hero in the game's fiction will take time to roll out correctly, and we'll share updates as this work progresses, " reads the developer update. "In the near term, we had planned to kick off a narrative arc in September supported with new story and game content, of which McCree was a key part."
"Since we want to integrate this change into that story arc, we will be delaying the new arc until later this year and instead launch a new FFA map this September. Going forward, in-game characters will no longer be named after real employees and we will be more thoughtful and discerning about adding real world references in future Overwatch content."
All things considered, I think this is probably the best move the Overwatch team could've done in their current position. Not only are they taking a stand against harassment, as small of a stand as that may be, but they're also using the opportunity to spice up Overwatch's lore. So if nothing else, at least we'll get the first big shakeup in Overwatch lore after nearly two years of stagnation.
Once the big update goes live I'll make sure to let you know. Until then, enjoy speculating about who everyone's favorite gunslinger really is!