It's true that atheists believe in miracles even more than theists in the sense that atheists think existence just popped into being from absolutely nothing, and for absolutely no reason at all.
Atheism only deal with the questions on the existence of any god, nothing more, nothing less.
Atheism isn’t study of anything. Atheism isn’t science, isn’t physics, nor biology. It is also not about any cosmology…including anything about any popping into existence.
You are referring to theoretical scientists in the field of cosmology, who might propose such thing…but those cosmologists might be personally be theists, atheists or agnostics, or whatever reli or philosophical background.
Do not acquaint atheists or theists or whatever as the same as scientists, because being atheists or theists are not jobs in any science.
Majority of atheists around the world do not work scientists in any fields, most of them work in all sorts of professions and trades, so a majority of these have zero position on the matter of cosmology.
You are generalising…put every atheists in the same basket.
Have you even bother ask any atheist members here, if they believe anything about things (eg universe, Earth, life, etc) popping into existence from nothing?
Ask them, and they will they don’t agree with this you making about them.
You would be surprised just how many atheists here, thinking this is just another strawman claim from you. You are being dishonest with your generalisation about the atheists here.
btw, I am agnostic, not atheist, and I don’t agree with this garbage you are claiming.