I appreciate the link, but I don't see what we gain by making these divisions between claims of knowledge and belief.
As I see it, behind all of this confusing machinery lurks a different debate:
naturalism. If someone is a naturalist, then it might make sense to say that atheism is a lack of belief. For a naturalist, everything is natural (unless shown otherwise). If there is no evidence for god, then god is taken to be unreal:
not without argument, but because the argument
just is the naturalist point of view. If we do not have any reason to think that god exists, but we do have reasons to think that everything real is natural, then we have reasons to think that god does not exist.
But we can step back and ask,
is naturalism true?, in which case this "agnostic atheism" is found to be exactly what it was from the start: atheism. One lacks of a belief in god because they do not think such a being is compatible with a naturalistic universe (i.e. they don't believe god is possible, they don't believe god exists).
I do not see how the supposed dichotomy between knowledge and belief is helpful. To be frank, nobody really cares whether you think (i.e.
believe) you know if god does/does not exist. All anyone should care about are the reasons for why you believe what you do. Perhaps this is related to the increasing need for people to apply labels to themselves as "identities", to differentiate themselves from others (to be individual/unique/special), while simultaneously belonging (to a clan/tribe/family); but that's just speculation on my part.
There's a simple test to tell if one is an agnostic or not. Do you know for sure if any gods exist? If so, then you're not an agnostic, but a theist. Do you know for sure that gods do not or even cannot exist? If so, then you're not an agnostic, but an atheist. — that link you posted
Does anyone know "for sure" if they will wake up tomorrow? Does anyone really care about "how sure" you are in your beliefs? To be clear: this is not about knowledge per se, it's about what someone
believes about their knowledge, which is not relevant. I wanna know why you believe what you do, not how confident you are in your beliefs.