Even if Phil is being truthful and intends to continue bolstering Xbox's first-party offerings, we won't see it for a while. Mattrick's decisions at the end of the 360's life and the Xbox One's original plan was a path they'd walked for several years. They basically assumed that Xbox gamers would be fine with yearly Halo/Gears/Fable/Forza, 3rd parties would still give Xbox a ton of exclusives, Indies would still be in love with XBLA, which meant Xbox could focus on "the casuals" with the TV/Kinect focus.
Truthfully, he shouldn't be praised for doing what they should've kept doing since the middle of the 360's lifespan
Why do people keep saying this?
Aquiring and founding new studios is precisely what Microsoft has done for the past five years. They haven't shut down an established studio since 2009.
We are seing the games coming out right now.
Project Spark in 2014 was Team Dakota's first game.
Halo 5 is 343 Industries' second game.
Gears 4 is The Coalition's first game
Twisted Pixel was aquired in 2011, and is currently working on its second game as a Microsoft studio (new IP).
Press Play was aquired in 2012, and has released 3 (or is it 4?) games since then. Currently working on a new IP.
Mojang was aquired in 2014. Currently working on more content for Minecraft. Too soon to tell what they'll do with the Minecraft brand in the future.
Rare, while not a new studio, should also be mentioned. They're finally making a core game again.
I don't think that Microsoft Studios in 2015 is perfect or anything. My point here is that the whole "MS was shitty and didn't do anything useful in the second half of the previous generation" narrative is bullshit.
The worst damage to Microsoft (Game) Studios was actually done in the 2007-2009 period when FASA and Ensemble were shut down and Bungie given back its independence.
After that, MS slowly started to rebuild its first party stable....and yes, it happened while Don Mattrick led the Xbox Division and Phil Spencer was the Head of Microsoft Studios.
There's still a lot of room of improvement, of course. I hope Decisive Games will be one of those improvements some time in the near future. It'd be great if they could get a few more homegrown teams off the ground.
To put some context on this:
We're still not seeing a large number of X1 1st-party exclusives. It's still Halo/Gears/Forza this year..
+
-Screamride
-Ori
-State of Decay
-Rare Replay
-Fable Legends
-Gigantic
...and so what if some of them are Gears, Halo and Forza? They're still first party releases.