$120 Bubble AK- FoxWoods SNG- BB sitting out

[Beerocrat]

Stack sizes are approximate. Villain seems semi-donkish, but somewhat observant. Probably around 25/10 for the game thus far.

Right before hands were dealt, BB takes a call on his cell and leaves, and is folded out. It then folds to Villain on button. How much do you increase the probability of him being on a steal with BB gone?

Blinds 300/600 75

UTG 1700
BTN 9000
SB 4300
BB 5000 (sitting out)

Preflop (t1200) Hero is in SB with AKo.

UTG folds, BTN raises to 2000.

There is a shorty, and I don't think I have any FE.

From SNGWiz it looks like a shove, if you assume BTN will call and input his bet as a shove.

Is it wrong to think BTN is doing this with ATC? He wasn't a maniac, but there were a lot of dead chips.

Thoughts?