Based on the radio interview I just listened to, the New Zealand Society of Authors seems to think they have invented the idea of a 'seal of approval' for self-published books. (Specifically applying an "objective standard" in terms of quality).The spokesperson suggested forming an independent authors guild (that name, by the way, is already taken) should take over that "traditional gate-keeping service".
I predict that will go as well as it usually does when you:
1) Become a gate-keeper without actually being a publisher who determines quality based on some kind of real world functional standard (e.g. book sell well, book gets awards), and
2) combine collecting membership dues with tell some of those members that their work is not good enough.
Which is to say: badly.