I'm not sure they "nabbed" him, he left Bioware last summer so he was a free agent for quite a while.
I'm hopeful that they can foster compelling content, both with indie development and bringing in the big budget ones.
I would assume Creative Director for Microsoft Studios likely isn't involved with their indie outreach programs or signing third parties at all. More of directing internal development from a high level. And as he states in that interview "my primary focus will be the creative direction of HoloLens Experiences".
I wonder how much EA's purchase had to do with Casey being willing to leave Bioware...
Bioware was purchased by Elevation Partners 10 years ago, and EA then purchased them 8 years ago. I think if that was the main reason he was leaving, it would have happened much sooner. Of course one could say maybe potential future stagnation was the reason he left, and that may be due to the current environment, but I would guess if he wanted to change course there were other projects to work on there.
Mostly I'm just worried that Microsoft is putting too much of their internal development time behind Hololens instead of supporting the Xbox One with great first party games that I actually want to play.