Yea, bring him up when he's not really needed, that's a smart move... Get that clock started for him, and if by some misfortune the Nats have to remove him form the 40-man roster, if they lose him in the rule 5 draft, that's perfectly OK.
With all the other talent in the system just as good, better and younger than he is, why move him ahead of the other prospects? Two and a half years in A ball, and now in his second year at Double-A, maybe the Nats know something we don't and that's why he's not been talked about. I'm not overly keen on anyone who progresses that slow, and 25 for AA, is getting up there.