https://www.gamespot.com/articles/overwatch-update-will-change-brigitte-mercy-and-mo/1100-6460522/

In addition to the above changes, Overwatch has a brand-new hero coming soon. Named Hammond, the character is a hamster whose in-game code name is Wrecking Ball, and he's launching on July 24. It's unlikely the above changes will go live simultaneously with Wrecking Ball's release--Blizzard merely states those tweaks "are coming to the PTR very soon."