I'm saying replacing a neuron or cell at a time within a quadrillion of them empirically leads to continued consciousness, and that assembling a quadrillion cells on a remote planet with no material connection whatsoever with the original body is a very different thing. You want to hide both cases behind the same word. I don't see why you think that's valid.
In your first paragraph, you say that we can take for granted that when an original is destroyed, having a replacement will preserve consciousness. Then, in your second paragraph, you say the opposite - that destroying an original would NOT preserve consciousness, even if there exists a replacement.
There must be some key assumption which lets you not see this as a contradiction. Maybe you believe that there is something extra-cellular which wouldn't get replicated in a teleporter?