And I think that is equivocation. If you say that a hat is red and I say I disbelieve you. I think it is a statement that the hat is not red.
You could be saying two things. 1) That you are withholding judgment due to lack of evidence, OR 2) that you believe that the hat is not red. But, a more appropriate analogy would be whether a baby on the other side of the world believes that the had is red. Although the baby has absolutely no idea about the color of the hat or whether the hat even exists, the baby would necessarily not hold the belief that the hat is red due to lack of familiarity/knowledge of said hat.
Either way, it is clear that being an atheist was used as a position. It was imputed on others based on their actions. It was necessarily a position. Agnosticism was certainly in that grouping, so "not believing or disbelieving" in a god would fit. But, only when that was a position one took or evidenced themselves taking.
The term "agnosticism" does not (and certainly did not back then) mean lacking belief either way. It has to do with gnosticism. "Agnosticism" is the belief that nothing is known or can be known of the existence or nature of God. Like the term "atheism", the meaning of "agnosticism" has changed since its creation. Now, it can also refer to someone who neither believes that God exists or doesn't exist.
It is what it is. You cannot change history nor can I.
As with the term "agnosticism", the meaning of the term "atheism" has changed since its creation. The original meaning of a term does not dictate its meaning now. As you are probably aware, many many english terms have changed dramatically since they were created. Think about the word "***" or "gay" or "nice" or "silly". All of these words have a completely different meaning today than they did originally.