DirectShow isn't explicitly mentioned, though yes, you could certainly use DirectShow to, say, implement a native Smooth Streaming source filter for Windows Media Player. We enable this scenario through the availability of the Smooth Streaming Client Porting Kit, but it's up to the developers to decide whether they want to use DirectShow, Media Foundation, WM Format, QuickTime, or any other media API to implement the client component. Note that I didn't mention any of those by name either. But I get your point - I could've been more precise.
DirectShow is not the only way to implement native media apps on Windows. Media Foundation (MF) is the newer, modern media API. That's what WMP uses primarily these days.
The focus of the Microsoft Media Platform is on streaming video. It's not meant to address local capture/encode/decode/playback (e.g. AVCHD acquisition) scenarios, but its goal is to enable over-the-top scenarios.