Alright, as a Mercy main and after derping around a bit on the practice range and failing to set up a custom game with bots (PTR is buggy), let me enter my two cents on Mercy 4.0 (? I'm bad at versioning) (don't worry, I'm not as toxic as bnet):
I don't believe that anything can be really a nerf, just a shift in playstyle. That happened with Mercy 2.0 (the one that moved rez to an ability from an ult), and I believe that is gonna happen now.
I will address three points: Guardian Angel, Valkyrie, and potential support duos.
Guardian Angel
GA was a Mercy's only way of surviving from enemy fire, her walking in heels ain't gonna cut it in the battlefield. This thus pains me to hear that GA movement speed (including when not in Valkyrie) has been reduced by 50%. I just do not see the need of reducing the GA movement speed when not in Valkyrie.
GA has a pretty predictable straight line to her target, and the bunny hop is not something many people will use instinctively. So it's not like you can't kill a Mercy when gliding, many people have done that to me in QP. The new GA movement speed felt like the movement speed back in Mercy 1.0 (the one when rez was an ult), when Mercies (I think this is the proper plural form) were dying left and right due to them not being evasive enough. This problem is only exacerbated when heroes with high movement speeds (Genji, Tracer, Winston, D.Va) came into the meta.
Now in the first paragraph I've highlighted when not in Valkyrie, and that is because the GA movement speed in Valkyrie should definitely be reduced. Her movement speed was so fast that if you clipped the top of a door you would be basically stuck there. It was extremely hard to get used to, because none of the other heroes have that kind of movement speed for that kind of duration, ultimate or not (maybe Winston's Primal and Genji's blade comes close, but not in the duration department).
Tl;dr, they should've only reduced the GA movement speed in Valkyrie and kept the speed when not in Valkyrie.
Valkyrie
As per my opening statement, nothing is ever a nerf, just a change in playstyle. Now that Valkyrie doesn't affect Resurrect at all, it will be a dramatic shift on when Valkyrie will be used. I believe, that instead of being a defensive and reactive ultimate Valkyrie will be used as a proactive ult. In other words, you use Valkyrie when initiating a fight, instead of saving (or trying to save) a lost fight. This once again shifts when her kit is effective. In Mercy 1.0, her kit was useful in the late-game. In Mercy 2.0 and 3.0 (the one with the rez cast time), her kit was useful in the mid-game. Now her kit is useful in the early-game. This shift is less pronounced amongst aggressive Mercies (like me), and they would be more adept in adapting their playstyle to better fit the new Mercy. Perhaps this is where Blizzard wants to take Mercy.
Support duos
As I've said before, I believe Valkyrie will now be used proactively. What this means is that the team will require a second support with a defensive ult that can sustain them through heavy fire (i.e. Lucio, Zenyatta, maybe Moira). This also means Mercy/Ana will not be a viable comp. Their combined healing is too much for all of it to be used effectively. Plus neither gives a defensive ult, meaning your team can be wiped out with heavy enough fire, regardless of support ults used. Mercy/Zen is probably still as effective as before. Mercy/Moira depends on the Moira player; if she focuses more on healing, then maybe it's not viable (same reason as Mercy/Ana not being viable). I still believe in my world where Lucio/Mercy is the support meta, but a man can only dream. A tank-heavy comp would likely run Lucio/Ana, since they have more useful stuff in their kits than Mercy's (speed boost, heal-deny nade, sleep dart compared to a 30-second rez).
Tl;dr, if Mercy remains solidly in the meta (which I doubt), then Ana's not coming back anytime soon.
#ISupportLucioMercySupportMeta