What was he realistically supposed to do? All signs point to A$G selling as soon as they could-right after they bought out Belkin, and after the rumored 7 year clause was up. They then began to talk with some California magnate about selling the Hawks, which was just a farce so that they could show the NHL that there were no reasonable offers for the Thrashers locally.
And there weren't, because no one in his right mind would buy the Thrashers, and only the Thrashers, with A$G still in control of the arena. But there were competitive offers for all 3, though it remains to be seen if the NHL could have blocked the move the Winnipeg on the grounds of that. Would have been an interesting court case.
But I don't think Waddell purposefully drove the Thrashers into the ground. More likely is that he was simply incompetent, and his efforts to improve the team were hindered by that and a lack of support from ownership. And what would have gained by saying "Yeah, they're going to move as soon as they can?" to the public? No free agent would want to sign there, and he would have been fired, and for what?
If he had a shred of integrity he could have said, "I want no part of this!" and gone public. ASG did much more than sell our team. They killed the market for NHL hockey in Atlanta and Donny the Wadd was their right hand man. What kind of hockey executive does that? And BTW, once the team was gone guess who was out of a job?