There's still rumours from evleaks & the like that they're planning to introduce AOSP-based Lumia(s), not upper bottom-end devices like the X-range. OR integrate an ACL, OR GFS* (instead of full-blown ACL & the downsides to that) into WP, so perhaps it's an exercise in shifting resources &/or reducing expenditure. *Google Framework Services (much of it prolly reverse-engineered)