I'm not saying she is or isn't, but if she were to (which would be foolish, IMHO, unless a genuine violate of contract was had), then she'd have to sue Debmar Productions.
Plus, I'm not certain the show is cancelled in the usual stance. I am sure, when/if Wendy is ever able to resume hosting, Debmar may consider resuming production. But, it is clear she is not returning anytime soon, and continuing to brand a show as The Wendy Williams Show without Wendy Williams is not something they wish to do.