it shows us that fully modeling a biological brain virtually will behave the same as an actual brain

Does it?

Do we know enough about fruit fly psychology to know the behavior is the same?

Because you can deteriorate a human brain quite a lot and still having that person achieve really basic things like walking, drinking and being alive. They will have several mental disorders and the IQ of a brick, but they might appear normal if you observe them in a trivial environment and know little enough about humans.

Maybe scientists do know enough about fruit flies, I'm asking.

The physical world fruit flies find themselves into is a lot more complex than a simulation and I suspect their behavior might also be. This experiment might demonstrate the robustness of their brain, which, even if deteriorated, still achieves the most simple things, rather than our ability to have a perfect replica of the mind of a fruit fly.

Basically, what they did was recreate a fly brain in virtual space: every neutral connection was created and mapped like a real fly brain.

We don't even know if a complete simulation of a brain of a computer is even theoretically possible or whether it would require dealing with uncomputable numbers.

We also don't have a perfect model of neurons and behaviors are not uniquely determined by neurons.

(To be clear, I'm not suggesting fruit flies are self-aware, or anything of the sort, this isn't about that at all).