“Atheists might favour strong emergence, they might be panpsychist or even idealist, they might even believe in transcendent morality and still not in a God”.

It all depends how one defines atheism. That is why I prefer the term non-theist to describe someone who doesn't believe in what you call a God. The term a-theist suggests someone who is completely outside the whole theistic debate, and I think should therefore logically accept materialism (or something very close). An idealist merely understands God as the Supreme Ultimate Cause (which is pure consciousness), rather than how Christians conceive God.