I think the irony that seems to get completely overlooked is that mobile device users may dominate the landscape of the future, but they are mass consumers of high quality content (from recipes to well-researched articles) that were created on devices with real keyboards and large screens.
So unless the roadmap indirectly is suggesting an abandonment of the user-generated content model, perhaps it would be wise to not be too hasty to ignore an entire market segment...
Now if we really want to dig into the nitty gritty of web usage, the fastest growing segment (although still tiny) for accessing the web isn't even mobile devices, but smart TVs... so if we're really "about the future," where does that fit into the plans?