All I can say is I hope anyone agreeing to appear in suit in adds or commercials reads their contract very carefully before signing and if they don't understand every last word, hire a lawyer to check it. It wouldn't be beyond the realm of possibility to lose control of the rights to your own costume. Certainly there could be some limits placed like you couldn't appear at events sponsored by competitors and such. This happened in Brazil. I'm not sure anything like this would even be considered in the US. Companies want to own the characters they use for advertising so there are no loose ends to worry about.
All I can say is I hope anyone agreeing to appear in suit in adds or commercials reads their contract very carefully before signing and if they don't understand every last word, hire a lawyer to check it. It wouldn't be beyond the realm of possibility to lose control of the rights to your own costume. Certainly there could be some limits placed like you couldn't appear at events sponsored by competitors and such. This happened in Brazil. I'm not sure anything like this would even be considered in the US. Companies want to own the characters they use for advertising so there are no loose ends to worry about.