One page one of this thread I posted an explanation of how infant Predators could accept some form of "milk". https://www.avpgalaxy.net/forum/index.php?topic=63159.0
I think if you study the inside of a Predator's mouth, and remove all the mental restrictions placed by years of practical rubber film effects work, it's easy to picture in my humble opinion a newborn Predator soft-tissue mouth accomplishing this. I personally don't have to do any mental gymnastics to make this work.
So we know that just because...
Predators appear Reptilian doesn't mean they are Reptiles.
Predators appear Humanoid doesn't mean they are humans.
Predators appear Crustacean doesn't mean they are crabs.
Though, if we look at totality, head to toe, it can be argued that from everything on Planet Earth, humans are probably what Predator bodies resemble the most percentage wise. Who knows, maybe humans and Predators do share a common ancient ancestry. I don't know. We all don't know what they are really. They are not of Earth, at least we think not. But there is no real scientific precedent we can apply to these fictional Predators.
So, I don't think any of us can suggest our opinions as definitive (including mine) because we're all talking about unknown fictional alien beings, which leaves a lot on the creative table to choose from and subsequently fun to discuss different preferences.