If you believe that God does not exist, you are an agnostic. If you KNOW he doesn’t, you are an atheist. I’ve “met” plenty of atheists on the internet. I’ve never personally met an Atheist, but I’ve meat plenty who claim to be - at first.
It’s interesting that nobody was making the distinction you make until relatively recently. I think it is the “refining” of the message as holes are found in it.
This is not an accurate description of agnosticism.
These are all semantic games anyway; these terms are all devised by men to describe certain belief systems, and since everyone's beliefs are relatively unique, blanket terms don't really frame good discussion.
Who cares what the word is? People can hold certain tenets of many different defined belief systems.