A connectome describes the connections between neurons. The weights are the degree to which the neurons are biased to fire or not and what you did with your training was to create those biases based on the training data. The actual weights are not in the connectome it is - as the name suggests - just a map. I wonder what the control experiment could look like, possibly a randomized connectome. And maybe it would work just as well as the fly brain. You can do the most horrible butchering of models and then train them back to functionality, this isn't all that different.