As Google stated, these warnings are suggestions for improvement. If you care about having your items listed as products in Google shopping, you should look into fixing the issue. If that doesn’t apply, you don’t necessarily have to address it. Typically for the best SEO, you do want to resolve this type of warning – if you don’t offer actual products, figure out what’s generating product markup and remove it, or if you do, figure out how to add the missing information.
