The latest Overwatch PTR changes grants Zarya, Reinhardt and, to some extent Reaper, buffs that aim at making them more viable in the current competitive landscape. Zarya's Graviton Surge negates all mobility options (in the same manner of Junkrat's trap) and Reinhardt swings his hammer faster with more efficiency. On top of that, Reinhardt's charge no longer damages himself when colliding with Doomfist or other Reinhardt charges.

Reapers change is a bit more nuanced. The voice and sound effects for Shadow Step have been "dramatically reduced", thus ending one of the oldest Overwatch memes involving Reapers laughable tendency to loudly announce his flanking attempts. It's not often a sound FX change will buff a hero, but a stealthier Reaper will undoubtedly be a more effective one.

McCree's Flashbang was slightly buffed and will now slow targets who are stunned. This means McCree will less likely miss stunned enemies because they are still sliding while stunned because of their previous momentum.

You can find the full PTR Patch notes here.