[dj-wonk]

You are talking about the aggregate demand–aggregate supply model, right? https://en.wikipedia.org/wiki/AD-AS_model

Here's my take: the paper would say that solving the AD-AD model with a computational technique with specific choices for parameters would not be considered a theoretical contribution.

I think that is an accurate characterization of economics, based on my experience of what 'theoretical' means. Why? When you use a numerical technique (i.e. not a symbolic manipulation) with particular values for the parameters, few would call that theoretical work. They'll call it applied economics.

(Side note: I can't speak from experience if the AD-AS model is usually solved with dynamic programming.)