Yep, pretty much. And even if they do reconnect, it is highly likely that their relationship will be different. Change in number of synapses, strength, even physical locations make a difference. Synapses at the end of a dendritic arbor affect the neuron differently than those that are close to the root. Even inter-synapse spacing is important, as adjacent synapses have modulatory effects on the reactivity of it's neighbors.

None of this is overly important per-se. Your brain doesn't have a specific pattern of arrangements that must be just so to make a human. But as you start changing these little details, the changes will eventually bubble up to create a different "you".

How much different is hard to say, maybe not even enough to be noticeable. This is firmly in "theoretical" territory. But considering how drastically people can change from relatively small strokes, I would hazard that there isn't a huge amount of deviance allowed.

Perhaps it's possible if you can do it finely enough that only single neurons are changing, allowing time to resynapse (or artificially recreating those connections?). Not sure.