The only clear historical grounding for neonatal circumcision is entirely abrahamic.
Never has this practice been associated to Egyptian infants. Otherwise they would show in Egyptian medical texts.
Some authors like Herodotus, Strabus, and Diodorus Siculus do seem to mention circumcision in Egypt but in the context of late teenagers and young adults, which links more to a puberty rite, or other coming-of-age traditions. It also didn't extend to all social classes.
Even so, late Graeco-Roman ethnographic observation (i.e. Herodotus) only reflects a period after Egypt had undergone several, substantial cultural changes including some brought by foreign rule such as the Nubian which 25th Dynasty, Assyrian invasion, Persian occupation.
So, I'd be careful in taking these claims as blanket statements that Egyptians mutilated babies, as that is the Historiyach narrative from Yehuboric enemies, and nothing more.
Like HPS Lydia said: it doesn't make sense to do something like that.