I feel like the sleep regression is really brought on by the baby's ability to recognise that they are hungry. Hence majority formula fed babies will sleep more

Obviously heavy sleeping EBF babies also can miss this step but if your baby is a light sleeper they will definitely keep waking up from hunger.

Usually the regression stops after a few weeks when either the baby can sleep through hunger or they start solids so something more substantial is in their stomachs

Anyway thats my theory.

P.S I know about recommended age , change in sleep and all that. I'm just taking a guess as to what it could also be. As a scientist I know information is ever changing and evolving based on continuous research so really we can't rule anything out