Yeah, an open platform with multiple vectors for sales, ecosystems of customers etc. There MS are keen to support that market as it makes sense to, through many of the ecosystems / stores that align - and integrate their own ecosystem.
PS Consoles, Nintendo are closed systems, and so are Xbox Consoles. To an extent they're pretty much competing in the same level with each other, which is why there is still exclusivity there to drive customers from one locked system to another. Only the IP that previously existed and happens to be so large ends up multiplatform in that sense. I imagine COD will be one such IP.
There is also cloud, which is one of their main efforts, where they'll likely push it as the option for people who are not on any other Xbox platforms, since it is gradually going to be the most accessible through the most devices, high quality and super low cost