[Update]: The latest patch has brought in experimental Assault (2CP) changes and Genji nerfs.
Due to the recent shuriken buffs, Genji has quickly become one of the most powerful heroes in all of Overwatch. In order to put a stop to his rampage and make it so ranked games revolve around more than just nano-blades, Blizzard has quite recently issued a small but reasonable nerf to his damage.
However, it would appear that Genji has become even more powerful than anyone could've expected as he has just straight up deflected these nerfs right back into Blizzard's face! And so, in a move that doesn't happen all that often with Overwatch, Blizzard has pulled back the update and will be releasing it again in the near future.
On a more serious note, the update has indeed been pulled back, though the exact details on why that has happened are currently unknown. According to Blizzard, the update hit some sort of snag, which I can only imagine is related to a game-breaking bug or a serious technical issue.
Whatever the case may be, expect to see the Genji nerfs arrive as soon as everything gets fixed up, potentially even tomorrow. Once that happens I'll make sure to let you know, but until then, you might want to get a few more Genji games in!
