I think the closure of Ensemble isn't a sign of Microsoft totally shying away from internal games development. Instead they appear to only invest where they feey feel there's either a lot of money on the table or where they need to fix holes in their console line-up. That is a little bit cynical, but it perhaps makes more sense for a platform holder than a more nonfocused strategy of just having big internal resources. For all the praise Sony is getting for their first party strategy, here we are 22 months after PS3 launch and there hasn't really been a game that would be a huge breakaway success (either commercially or critically).
Ensemble is (was) of course a very good studio that was always profitable with a very successful IP, but Microsoft probably think they don't need a RTS studio. Halo Wars might be a solid game, but it won't make the genre suddenly huge, because even on PC it has its hardcore fans, but doesn't seem to have much audience outside of it.
In similar way, Microsoft had a much bigger number of studios back in Xbox 1 days, but it didn't make a slightest difference. Right now each of their studios seems to be focused on very specific market and in future they'll be opening/acquiring new studios with that in mind, rather than growing for the sake of growing.
Ensemble is (was) of course a very good studio that was always profitable with a very successful IP, but Microsoft probably think they don't need a RTS studio. Halo Wars might be a solid game, but it won't make the genre suddenly huge, because even on PC it has its hardcore fans, but doesn't seem to have much audience outside of it.
In similar way, Microsoft had a much bigger number of studios back in Xbox 1 days, but it didn't make a slightest difference. Right now each of their studios seems to be focused on very specific market and in future they'll be opening/acquiring new studios with that in mind, rather than growing for the sake of growing.