Blizzard are going to nerf several Overwatch heroes in the next patch, including Reaper, Hanzo, Sigma and Baptiste. However, the star of the show is Orisa who will get suplexed by the balance team in order to let other tanks have some fun too.
Blizzard added another batch of balance changes to PTR on 23 January 2020. These changes will be tested and most likely make it to live servers in the next patch but it's not guaranteed they will remain in this form.
McCree is the only one on the list who wasn't outright nerfed. Technically he was, due to getting a slower fire rate and therefore lower damage output but his health got a bump from 200 to 250. His recovery from Deadeye will be better too, since his crosshairs won't get locked during the firing animation.
Reaper was buffed back in the days of GOATS meta when we needed a hyper tank buster, which ultimately proved to not be enough to stop this composition. With 2-2-2, he is now a bit too effective and players aren't keen on seeing him heal for 40 per cent of damage done. This number will be slashed to 30 per cent. If you still can't counter him, try turning a fan on.
Sigma's primary fire range has been slashed from 22 to 20, his slow from Gravitic Flux is down from 0.9 seconds to 0.6 and Accretion damage is down to 40 from 60. In other words, you might be better off with another tank.
Orisa received a similar balance beating as her primary fire will now deal 9 damage per shot instead of 11. Furthermore, she should be even squishier without a barrier in front as her Fortify cooldown is going up from 8 seconds to 10. Halt nerf is probably the most damaging one since the window to combine it with power of her DPS heroes will be lower as the snare will last 0.65 seconds instead of 1 second.
As Blizzard keep nerfing barrier heroes, it is quite obvious they are trying to weaken bunker compositions and make the meta a bit faster. Baptiste is the perfect healer for such compositions so he will get slapped too. Biotic Launcher's primary fire will be roughly 25 per cent slower now to push him more into the healer role but that part has been nerfed too since his grenades will heal for 50 health instead of 60.
You can check the full balance changes and players' reactions on the official Overwatch forum thread .