It’s strange, in many ways, to be back, or at least back under these circumstances, watching Doctor Who tick down to the first time since Time of the Doctor [2013] that an episode will air when the next episode hasn’t been shot. And that was a two week period towards a commissioned episode—Deep Breath shot in January [2014]. Here we head towards the great unknown, perhaps even the wilderness. It’s faintly unsettling—I’ve not written about Doctor Who in a moment where it might not come back before.

— Elisabeth Sandifer, in her review of "The robot revolution"

I'm not going to wallow in predictions of doom and gloom here, just note that what Sandifer outlines here is fairly out of the ordinary. It certainly shows that the joint venture with Disney hasn't played out as expected.

To rewind a little, when Russell T Davies returned as a showrunner, he announced that an initially two-season distribution deal