I would say “no” because atheism is simply the absence of belief in something that there is no evidence for.
If I returned from a vacation in the Pacific Northwest and claimed that I saw a bigfoot, would not believing me if I failed to provide evidence be a religion? No, it is simply not being gullible and accepting something without proof. It would be my responsibility to provide evidence, photograph, hair sample, body. So, unless believers can prove that their god exists, I have no reason to accept their claims as valid, especially considering the contradictory characteristics of the god they claim is real. BTW: I am sure that they don’t believe in Zeus, Apollo, Thor, Isis, Horus, etc. but do they have evidence that these gods to not exist? So, why, then does anyone have to disprove their god.
Myth: Believing Something You Can’t Know or Prove is a Religion
A very nice article for those who may be interested.