Personally, I don't think this person works at Microsoft based on things he has said so far, I feel like most of the time he is over-simplifying things. I'm going to give my take on what he's "revealed" this time.
1)This entire point is vague. Not sure what he is referring to when he says our architecture isn't ready. If he is saying our architectural design isn't finalized, that is completely wrong. I'm going to assume he means certain features aren't fully ready to be shown, which is true. That being said, I don't see how this has anything to do with Microsoft not streaming Gamescom. Perhaps he meant because some of our features are not yet ready, the overall experience will be so terrible, streaming the conference would show how badly our console runs. Well, we will have 100+ playable consoles at Gamescom. Clearly not the case. The official word has always been Xbox One will launch in November.
To say that our latest July/August DurangoXDK (I assume this is what he meant by SDK) dropped performance by 15-20% across the board, this would mean I as well as a lot of people seriously screwed up somewhere, and I should be freaking out right now. Last time I checked the perf tests, they are on an upwards trend.
2)There are no yield issues I have heard of from my leads, their leads, or our executives. What was told company wide is we will sell 100% of our production inventory on launch based on pre-order numbers. Every console we make until launch will need to go out the door. There is the possibility of our executives simply not revealing the yield issues to us because they don't want to hurt morale. I doubt this is the case.
Points 3, 4, and 5 I have no idea.
6)This isn't news. Marc Whitten has publicly said that the every console will be a dev kit functionality will not be ready at launch and added at a later date. More info will be shown at Gamescom.
7)Not news again, the same day Marc Whitten revealed the Kinect does not have to be plugged in, we confirmed there will not be a Kinect-less Xbox One at launch.
On the possibility of this happening March/April 2014, I have no idea. But to say the Xbox One's launch numbers will be a fallout is unfounded.