AKs and AKo are drawing hands preflop. They should be folded preflop accordingly generally because you can't tell the difference between an AA (almost drawing dead), KK (basically drawing dead), or QQ (still a little less than a coinflip) all-in. I cannot imagine a call with AKs/AKo against any reasonable opp's preflop all-in over a large sample of hands would be +EV for this reason.

AA is not a drawing hand preflop (never folded).
KK is not a drawing hand unless it's against AA preflop (1 out of 23 times or better, I think, so folding it is kind of absurd most of the time, i never fold it anyway).
QQ is not a drawing hand unless it's against KK or AA and hardly better than a coinflip against AKs/AKo (1 out of 11 times or so or better, i fold this against two all-ins or a tight player's all-in).

This applies to any no-limit game (SnG or ring). A 4bet preflop in a limit game I'll play AKs for flush draws or aces/kings paired or both given community cards.