I suspect they want to diminish the concept of console generations altogether and push towards an "xbox as a service" type idea. Looking at how they've mention

I suspect they want to diminish the concept of console generations altogether and push towards an "xbox as a service" type idea. Looking at how they've mentioned that owners of their new first party titles on xbox one will have an upgraded/enhanced release available at no cost on their new console - I suspect this is to blur the lines between the two series.