I'd like to believe this, but it seems to fly in the face of every other discussion about true resolution of 35mm film that I've ever read, even our own Ralph Lambrecht in his book Way Beyond Monochrome, (which I love by the way if you're reading this Ralph.)With the modern, fine grained films, a remarkable amount of detail can be recorded.
I would agree on the issues of color capture and bayer, but it isn't as simple a conversion (100 to 400) as your note suggests. For one thing, luminance is captured at every pixel, but as you state, color is interpolated across pixels. This does create problems in certain cases (those small very red berries might be hard to capture cleanly in the d* world, and might get interpolated away color-wise, but their luminance would be captured I believe).
Not to defend that, or belabor a d* discussion, but I think I'd get slapped down pretty hard trying to claim that my Oly 35RD was equivalent to a 400 megapixel d* camera, or even 100 mp.
Ralph if you are reading, any thoughts?