It definitely wouldn't be murder, so long as Eliezer agreed to the procedure. At worst it would be assisted-suicide. I would even go a step further and say that it seems plausible that killing the carbon version might be the only sensible long-term economic decision.
Imagine if there were a small number of Mt. Everest-sized humans who needed massive amounts of food to stay alive. They are sentient, but think far more slowly than regular humans. They subjectively experience only a couple days every sidereal year. Because they need so much food, and think so slowly, they can't do much productive work, and to survive they collectively need trillions of dollars of resources donated from the world's governments.
Or what if the 'mountain people' are utterly microscopic mites on a tiny ball hurling through space. Ohh, wait, that's the reality.
sidenote: I doubt mind uploads scale all the way up, and it appears quite likely that amoral mind uploads would be unable to get along with the copies, so I am not very worried about the first upload having any sort of edge. The first upload will probably be crippled and on the brink of insanity, suffering from hallucinations and otherwise broken thought (after massively difficult work to get this upload to be conscious and not...
In this video, long about 48:00, Eliezer talks about uploading and about how it wouldn't be murder if his meat body were anesthetized before the upload and killed without regaining consciousness.
It's arguable that it wouldn't be murder, but I'm not clear about why Eliezer would want to do it that way. I've got some guesses about why one might want to not let the meat body wake up (legal and practical complications of a double but diverging identity, the meat version feeling hopelessly envious), but I'm not sure whether either of them apply.
On the other hand, I can think of a couple of reasons for *not* eliminating the meat version-- one is that two Eliezers would presumably be better than one, though I don't have a strong intuition about the optimum number of Eliezers. The other, which I consider to be more salient, is that the meat version is a backup in case the upload isn't as good as hoped.
More generally, what would folks here consider to be good enough evidence that uploading was worth doing?