Yes, I think Trump did the same thing, but the difference is he won. If Sanders had won enough votes I think he would be the Democratic candidate, no matter how little officials of the DNC or old Party members with an office that gave them superdelegate status felt about him.
I agree that the use of superdelegates is not perfectly democratic, but the Parties are not government agencies with an obligation to everybody's ideas about fairness. Sanders knew about the superdelegates relationship with Clinton going in. That's exactly why Parties have mechanisms like that, so they will resist hijacking from outsiders.
