The question is not whether we'll ever be able to "upload" a map of a neocortex, but rather whether we'll be able to transfer the will and sense of self that makes us who we are.
Perhaps at the time technology is able to upload a map, we'll discover that we really are nothing but meat machines. But I believe there is an extra "something" in the specific timings of how your particular neurons fire and interact with each other that makes you you. Not really a soul, per se, but a "something" bound in the chemistry and biology that we haven't even begun to measure or analyse. An essential "spark", shall we say.