WE certainly are seeing a lot of extremely skilled defensive players and athletes in CF in the AL.
Buxton, Kiermeier, Hicks, Pillar, Zimmer, Trout and Leonys Martin for starters. I haven't seen Dee Gordon out there yet.
And the NL has Cain, Pollock, Inciarte, Hamilton, and Brinson (who Fangraphs loves defensively, but I've never seen play).
I named about a dozen extremely talented defensive center fielders, the existence of whom doesn't negate Jackie's ability to play the position.
Not sure why it is so improbable...