Is it possible to set up Autosuggest terms for non-product queries?

Yes. If the search term is a popular query it will automatically be added to the list of autosuggestions. For example, a non-product query such as "returns" will display as an option in the Autocomplete UI. In addition, if there is a redirect set up for "returns" the user will be redirected. Autosuggest terms can also be created directly through the Customer Dashboard or via the API.