Yesterday, Blizzard released a new Overwatch update on PlayStation 4, Xbox One, and PC, adding the Summer Games seasonal event, which runs until August 22 and includes over 100 seasonal items and the new Lúcioball.
The update also included a number of improvements, bug fixes, and balancing changes, which you can see in the patch notes below (apply to all platforms; PC-only changes not included):

General Updates
Competitive Play

Players who leave a competitive match before its conclusion will now have to wait for at least 10 minutes before joining another competitive match
During subsequent rounds on Assault maps (Hanamura, Temple of Anubis, and Volskaya Industries), the amount of time provided for team assembly has been reduced

Miscellaneous

Added Lúcio as an AI hero in Practice vs. AI, Play vs. AI, and Custom Game modes Several minor, behind-the-scenes improvements have been made to the in-game matchmaker

Map Balance Updates

Made several minor adjustments across Watchpoint: Gibraltar to ensure better balance for defending and attacking teams

User Interface

Zenyatta’s Transcendence speed increase is now noted on the Hero Details screen
Players can now select which type of Loot Box (standard or seasonal) they’d like to open next

Made several minor improvements to the way hero selection tips work:

The “No Builder” and “No Sniper Hero” warnings have been removed
“No Support Hero” now reads as “No Healer” ...