Interesting video that may have valuable information. Two points, though:
1) Does anyone else find it curious that a Ford tech would go public with potentially damaging information that Ford hasn't released yet? The guy is identifiable and even has a name tag. Maybe he's just brave.
2) He's diagnosed poor DI cold engine performance as caused by intake valve deposits. But, this is a problem associated with PORT injected engines: fuel is absorbed by carbon deposits on cold intake valves, making the mixture leaner than intended. In a DI engine, fuel never washes over the intake valves so no absorption occurs. Maybe there's another explanation but to me it seems he has mixed DI characteristics with PFI problems.
Mind you, I'd be reluctant to buy a new EcoBoost engine, too, but am not convinced this video tells the whole story.