I don't think that's true. Babies are 'atheists' in the sense of not being part of any particular theology because they simply cannot comprehend the complexities of such belief. All it means is being void of theological belief ( religion) but obviously it doesn't mean they are militant neolib/socialist atheists either who are clearly ANTI-theist ( not just atheist).

Personally I consider myself more of an atheist but honestly I can't stand most atheists with their religious-like convictions and appeal to neoliberalism and socialism. Political atheists are just as bad as fundie Christians in my opinion and just as annoying as Allahbots.

I don't think a baby has the cognitive development to even comprehend divinity or lack of.  If anything wouldn't a child consider their mom to be "God?"