Although few sites buck the tradition to have the www subdomain be handled identically to primary domain, it is not a requirement to do so. I don't have example

Although few sites buck the tradition to have the www subdomain be handled identically to primary domain, it is not a requirement to do so. I don't have examples flowing out of my pocket, but it's just a DNS configuration away from reality. You could also phrase this as the distinction between being "correct" and being "right". The current solution is "correct", although the proposed solution will typically be "right".