It's my understanding they're going the same way as it seems Jolla might also end up doing, by using libhybris with Android drivers. Apparently the chipset manufacturers have no interest in X11/Wayland/Mir drivers due to perceived low volume (probably justifified perception at least in short term). Using Android drivers is a way to get in to the game, and perhaps when there's enough volume the chipset makers can be persuaded to make dedicated drivers.