It's not plausable, for scientific reasons. It's at best an hypothesis with as yet no evidentiary support. When atheists say there's no God, they mean the probability is so close to zero, that one can say such a thing with a high degree of confidence. Just like disease cannot be explained as an imbalance of the basic elements of fire, water, earth, and air. The early universe is know known to have been a place of extreme entropy, where no complex structure could exist. No supernatural thing exists. It's part of science to withhold absolute judgement on things, but that doesn't mean to ignore what we do know.