I fully expect to hear howls of "unfair to it's competitors" from some parts.
It sounds like a really good idea, and an extension of the way it already works given some series make earlier episodes available until a week after the last one, but I can also see it raising complaints from some other broadcasters and the likes of netflix.
They've tried similar good ideas in the past but had them shot down on "competition reasons" when they've gone for approval, only for the competition to never turn up.