The OP would not be stealing. Possibly the person they sell the receiver to might intend to do that, but it's not the OP doing the stealing.
It becomes a personal judgment call whether anyone thinks it is ethical or not for the OP to provide the requested information. One one hand, the OP has no legal responsibility to protect Dish from potential theft. On the other hand, the OP may not wish to give out the information because they think it is wrong. Everybody can judge whether it's wrong or not for themselves. It's a gray area, subject to interpretation.
If find it hypocritical that Iceberg says the OP would be doing the wrong thing by giving out the info, calling the OP a thief basically (or at minimum, "assisting a thief"), but then goes on to say this:
...I've "moved" numerous times. In the 7 years I had Dish, I don't think my address on file ever matched where I actually lived
Iceberg, I think what you did was the wrong thing there. But that's my opinion, and evidently not yours. So I wouldn't chastise you about you did. Although I do wonder what would be the purpose of giving false address information to Dish. Maybe Dish would consider such a thing as "theft", but you wouldn't, so then it's OK. Right?
Minor issues. Gray areas. Subject to individual interpretations. Nobody is right, nobody is wrong. If everybody saw every issue in the same way this planet would be a very boring place to live.