4ish orders of magnitude’s between fly neuron counts and a human’s. Not to mention mammals tend to have more synapses per neuron than invertebrates.

So I’d say, no humans are not next.

Probably easiest to go to fish next for simplicity, but with the prevalence of mice in neural studies, maybe we’ll skip fish and move right on to mice.

Then to some primate(s), maybe working our way up through several species.

Then humans.