That has been the CBC's position a number of times—certainly, most recently, dealing with them in the documentary project that Telefilm and the CBC put together to do theatrical documentaries. The CBC was initially insisting on a first television window coming on the heels of the theatrical release, which really, in some cases, would have pre-empted the exploitation in the home video market, though I understand that as this project has been renewed the CBC has understood that an orderly window is necessary for it to be considered a theatrical film and to maximize the revenues.
On May 1st, 2007. See this statement in context.