This actually happens with people preferring books to ebooks or vinyl records to MP3 files.

But anyway, I'll respond with a second hypothetical.

Gasoline Gal is married. She expressed a preference that her husband remain faithful to her, and being old fashioned, even made sure that her marriage vows promised faithfulness.

You are not trying to convince her to accept either hydrogen engines or uploading. Rather, you are trying to convince her that she should not prefer that her husband remains faithful to her. At most, she can prefer that her husband remains faithful to her as far as she knows. As long as she does not know and cannot detect his unfaithfulness, it causes no harm to her. She objects, of course, that it could cause harm in some indirect way (such as increasing his chance of passing a STD to her), but since this is a hypothetical, you say "if your husband cheats on you, but because of some circumstance, this doesn't increase your risk of STDs or otherwise cause you any physical harm, and it causes you no mental damage because you don't know about it, is he wronging you? And is this a situation you shouldn't prefer?" You say that he has not wronged her and she should have no preference against that situation. Indeed, you're not even sure it is meaningful to have a preference against that kind of situation. She disagrees. Who is right?

This is related to the fact that utilitarianism is bad at handling blissful ignorance situations although the problem is by no means limited to utilitarianism.