No, most teams, in fact almost every team, has a young, athletic, fast center fielder. Which is why I don't understand why Ellsbury wasn't in center with Cameron left to start the season. If Cameron was in left, even if he lost a step, he would still be an elite defender and still provide the Sox with a great defensive outfield.
When CF's get older they usually move to right field or left field, which it was odd for me to hear Cameron had a great UZR last year in center for the Brewers,