opens with a scientific claim based on atheism
Firstly, not really. Atheism is a lack of belief in gods, the statement made was that proper science education could dissuade people from a belief in heaven. They're different things - unless you want to change the meaning of atheism.
Secondly the claim is made by an atheist but is not a claim based on atheism.
poses a question whether atheism is beyond the purview of science
Atheism is a lack of belief in gods - that's it. The question is ultimately pointless.
and that's science?
No, that's an opinion based upon certain factors.
I lack a belief in gods and werewolves etc partly because I have learnt, understand and agree with the scientific method and as such am less likely to "have a belief in heaven", (or other such things outside the scope of the scientific method).