And even if Coleman did try to sue the show it would be a very fast and unsuccessful lawsuit. This is of course due to the fact that satire is legal and that is the reason why Sesame Workshop hasn't sued the producers of Avenue Q as well. You can spoof something or someone all you want without it being against the law.
I have always thought that the role was being played by a woman due to the fact that Coleman himself has a higher speaking voice then the typical male, and that most of us remember him as the little kid on Different Strokes etc. But, i wonder if the role is going to be played by a male when the show moves to New World.
And, just to throw something into the mix, while the role is played by a male actor in London, during the course of the show's run, there have been both male and female understudies for the role.
"If you try to shag my husband while I am still alive, I will shove the art of motorcycle maintenance up your rancid little Cu**. That's a good dear"
Tom Stoppard's Rock N Roll