That espn article doesn't explain that reasoning but it does offer this nugget:
"The locks are identified; Ryan Suter, Paul Martin, Ryan McDonagh and Brooks Orpik, whom the coaches are emphatic they want on the team."
Bylsma is the coach, he wanted his players. Orpik and Martin were locks from the beginning while Yandle had to battle against the Johnsons, Seth Jones and Byf.
Reading that article is just so damn frustrating. They say they want the best players but leave out Ryan and Yandle, two of the highest scoring Americans at their position. And Okposo, the 2nd highest scoring american this season. They seem to be all over the place with their reasons, and I can't stomach their quick dismissal of Bishop for Howard. They claim they looked at more than this season for players and that helped Howard get selected, but it is obvious they didn't apply that same reasoning to some of the other ones they left off like Erik Johnson (who played well in Vancouver) or Ryan. They claim that they wanted to focus on Dmen who could move the puck up to the Offense well, but leave Yandle off the roster, they said Ryan doesn't have enough PP points this year to justify a roster spot, I mean forget the fact he is on that Ottawa team...
The way they bash players, who will no doubt read that article, is mind boggling. It be very interesting to see how they do this year and if they don't do well it will be interesting to see where the US is in four years.