That I keep seeing more and more posts from moms saying "what do babies eat until your milk comes in" and "can I refuse hospital formula until mt milk comes in" and "how long can a baby go without eating after birth, cuz my milk won't be in yet"

It's called colostrum. It's what your body produces before milk. It's very rich in nutrients and it's what baby needs in those first few dsys. Please, Do NOT deny your hungry baby food because "your milk hasn't come in"