Agreed. I'm not suggesting that Microsoft needs to announce a price soon or even within the next 9 months.
What I'm saying is that because price is not going to be announced anytime soon, more devoted gaming communities like this one will keep suggesting how likely it is the price is close to $399 whether that's based in reality or not. The more we speculate about how great this system could be -- based on very little hard data but enough to get us to imagine the possibilities, the more we rationalize potentially purchasing the system which makes it less likely we'll back out once the hard data (price, specs, etc.) does get announced next year.
It really is a brilliant PR strategy because it takes advantage of our natural tendency to speculate and ultimately desire new gaming hardware.
On the other hand if people really believe that $399 is possible and then Microsoft announces it at E3 at $499, it will be viewed as a huge disappointment and most people will indeed back out because you spent rationalizing getting one at an imaginary price that actually doesn't exist.
That's why I believe Phil Spencer keep giving this kind of interviews warning about this being a premium console with a premium price. He already said this console is made to the hardcore/4K TV owner market and trying to set expectations so that people don't get disappointed.