That's not correct. The Pricelists are not only used with product.product. You could use it with product.template and product.category. The sale.order is the responsible for validate if the pricelist apply or not to the sale.order.line products when calculating the price_unit for the sale.order.line. You could create a dynamic domain that could filter products on the sale.order.line based in all the pricelist version elements but also it's not correct because only one pricelist version element is selected when computing the price_unit and is the one that best matches to the sale.order.line in terms of (product, qty, sale date and sequence of the pricelist version element, min and max margin specified that also could be based on another pricelist). So you could filter for all the products that matches the pricelist final target products(not an easy task) but it's not recommended.

Only my opinion