playoverwatch.com/en-us/blog/20243886

td;lr:

Genji got nerf on animation cancel(can't immediately dash after melee), double jump+wall climb, and ultimate duration(6 instead of .

D.Va got a nerf when regenerating her defense maxtrix(it's now 1 second instead of .5)

Hanzo got buff in his speed while aiming(30% decrease instead of 40%) and projectile speed(30%)

Mei got buff in ultimate, now it can pierce barriers like reinhardts shield and it's radius is 10 meters now.

McCree's ultimate got nerf also applies to all heroes with this function, but his deadeye will decrease by a .25 period instead of just being 50% if not used(This means that your ultimate meter will start reducing faster)

Mercy's healing per second got increased(20%) and allys can be back into the fight quicker when rezzed(2.25 instead of 3 seconds).

Lucio got nerf on his amp it up on only speed(30% decrease, so instead of 100% on speed when amped, its only 70% increase)

Zen got nerf to his discorb by 30% but his damage got increased to 46

and finally If Roadhog's hook manages to hook someone that's not in his sight, they will be reverted back to their original position(So a kinda nerf to his wall hook bug).

They also reverted a recent change to reduce size of heroes' projectiles so welcome back pro hanzos lmao.