The problem with most of these kinds of analyses of groupthink, is that everything they say is a characteristic of groupthink, is also characteristic of achieving consensus of any sort. We don't call it self-censorship unless it turns out badly, because the absolute lack of self-censorship is cacophony where nothing is ever decided. "Belief in inherent morality of the group", is not what we call it when it turns out that, say, those in favor of abolitionism _were_ in the right. We only call it that when it turns out to be false.

I've seen cases where you actually lack all of the things listed here, and they are groups which are never able to agree on a course of action, or cooperate to achieve anything. You call it either "agreement" or "groupthink" depending on whether it turns out to be good or not.

Which means, that a list of "symptoms" like this will not help you to discover in advance whether the group in question has a problem, which is what is actually needed. It's something that can give you the comforting illusion of being able to detect groupthink ("it won't happen to me"), without in fact helping you actually notice when the group you're part of is heading off in the wrong direction.