Its odd though - i would assume a conference of this size would have penalties in the contract if the venue decides to pull out without cause or sufficient notice.
To a point yeah but the venue also has the power not to sign the contract in the first place (ime the venue is the side typically negotiating from the position of power) if they think the penalties are too high on their end.
In all likelihood they ran the math and figured it was worth it to yank the rug out from under Defcon, penalties be damned.
In all likelihood they ran the math and figured it was worth it to yank the rug out from under Defcon, penalties be damned.