Did they previously have client-side validation of the self-signed certificate, and now they changed it to "accept any cert signed by a root CA"? If so, why in

Did they previously have client-side validation of the self-signed certificate, and now they changed it to "accept any cert signed by a root CA"? If so, why in the world would they do that? Maybe I'm being hopelessly optimistic by not jumping to the conclusion that they did no validation whatsoever before?