It took long enough, but some people are finally seeing the light and realise that Sylvanas is an evil bitch. We were told years ago that she was using the Forsaken as tools for her survival. Of course, she can accept that others are turned into puppets if it helps her reach her goal (although she seemed to have some very brief qualms about it where Anduin is concerned)! It's her becoming a puppet yet again, like she had been under the Lich King, that she can't accept. Is it hypocritical? Well, yes of course, she's evil! All this "We are all in prison! I will free us all!" It's all rationalization. She actually doesn't give a damned about what happens to our characters. She just wants to be spared the eternity of despair and suffering she experienced when she commited suicide.
"I will not serve." People put emphasis on the word "serve", but "I" is just as much important, if not more. It's the most important word in her vocabulary.