I'm sure that would be considered a viable option if we had the tech, but brain-in-a-jar feels more achievable in the nearer term to me. It also allows for continuity of self/culture, which is important to a lot of people.

The idea of infants being raised to adulthood by machinery in unknown conditions to start a new civilization seems more like branching into a different species when you really think it through. I have greatly enjoyed this story line in fiction, but I honestly don't see it as remotely realistic for many, many decades if not centuries. Unless we stumble across the Singularity or something, haha.

It is incredibly presumptuous to think a connectome scan is even a fraction of the full-state of the brain.

We are quite a ways from fully understanding even a single neuron.