For those who can't watch the video/are not bothered:
-Console Version can't use the PTR, because logistics of multi platform.
-PTR allows developers to "update" PC without officially patching until they can release on all platforms relatively close together, because of the approval process for consoles.
-Sombra will be gradually changed, meant to be a disruptor/assassin. They believe she's very powerful and that players still haven't mastered her. With that said, they have a plan to gradually keep bumping her up as needed until she catches on.
-Roadhog got nerfed and buffed because there were legit complaints from both sides and the team had to address both.
-D.Va doesn't have the same window of weakness as other heroes, because she doesn't reload. When she's outside her effective range she simply uses her mobility, and when she's outgunned she turns to defense matrix until she can leave. With such high survivability between Defense Matrix and boosters and doesn't have a reload window of vulnerability, she needed to be reeled in. They will scale back the nerfs if its too much, however.
-Ana will not receive dramatic changes & are content the way she's built. They do agree that she needs to be scaled back.
-They are listening, both to feedback from players and from statistics coming from the PTR itself. However, the feedback can be misleading as people who are happy with changes are less likely to be on the forums talking about it, while players who are unhappy are more likely to be vocal. The changes on the PTR account for both sides and for the numerical feedback they get.
Personally speaking, I'm not looking forward to playing the game with lackluster D.Va again and getting yelled at for playing her and not being able to do my job fully. Especially if their patterns on updates stay the same. I am still going to worry, because this does not change what they said about her in their on the official forums. But I hope they will listen to players to fix her, and don't wait another half a year to do anything to D.Va.
Sombra is whatever, as I don't play her and have no interest with trying her out. I'm fine with Roadhog & Ana's changes (Pig Boy really feels better to play now), but I agree that Ana needs some additional readjustments so that she isn't such a healing monster.