I think you are misinterpreting what he is saying. Direct3D is built on COM so the DirectX 1.0 COM interface still exists and code written against it should still work. However Microsoft has tried to make each version of the API internally consistent and as good as possible, so new versions of the API don't keep legacy junk sitting around.
OpenGL on the other hand has made sure that OpenGL1.0 code is still valid in current OpenGL(Pallet swapping FTW). Though I find it a bit odd that he is making that comment now. OpenGL 3.0(back in 2008) started the transition to a modern API. It deprecated the cruft and started building for the future. OpenGL 4.0 was released a year ago with all the deprecated stuff removed, and is now a nice clean API that is actually pretty close to DX.
OpenGL on the other hand has made sure that OpenGL1.0 code is still valid in current OpenGL(Pallet swapping FTW). Though I find it a bit odd that he is making that comment now. OpenGL 3.0(back in 2008) started the transition to a modern API. It deprecated the cruft and started building for the future. OpenGL 4.0 was released a year ago with all the deprecated stuff removed, and is now a nice clean API that is actually pretty close to DX.