Is an artificial neural network a kind of metaheuristic?
I suppose one could possibly argue it either way, but at the end of the day, it doesn't really matter whether we classify an ANN as a metaheuristic.  It sounds like you have one reader who found it off-putting or confusing to have you compare ANN vs metaheuristic because they would have characterized an ANN as a metaheuristic.  So, I suggest asking yourself three questions: (1) How many other readers will have a similar reaction?  (2) What changes can I make to the paper that would avoid that reaction?  (3) Is there any downside to those changes?  Are they worth it?

In this case, it seems easy enough to rephrase your description of the comparison, so you don't trigger this reaction.  You could be more specific about what comparison you are doing: you compare an ANN to a genetic algorithm.  That might avoid the problem, with no downside.  Being specific is often a good thing.