No.
Edge flow basically is how you position your edges.
If they support the overall shape/mesh and arent just randomly all over the place.
Its mainly important to have a good edgeflow for rendering/shading.
For a game like gunz its not all that important as it works with smooth groups and some other reasons.
Though you shouldnt forget about them.
(Just a random model i had around)
Doesnt display perfect edgeflow or even show much at all cause its basic but still.