The article blames, in part, this clusterfuck on the fact that the White House has lacked a communications director since March. That indeed may be part of the problem.
But I see a more fundamental reason why -- you have a White House with an utter disregard for the truth. When everybody has carte blanche to lie, those lies will contradict each other. But when everyone more or less tells the truth, then the stories would match.
The lying problem starts at the top with Donald Trump. And he's getting worse on this front. A number of major media outlets in the last week have noted his pace of lying has increased. The Toronto Star, for instance, published a piece yesterday (link here) with the title "Donald Trump said 71 false things in 14 days. His dishonesty is increasing."
Logic dictates at some point, and perhaps soon, his lying will reach a sort of critical mass where even his allies will turn against him, fet up with the incessant lying. He'll burn too many people he leans on, and their loyalty will run out.
Let's hope that happens soon.