Being born of water could have spoken of the physical birth . . . being born of water. Christ told Nicodemus he must be born again. Nicodemus asked how is this possible, a man cannot re-enter his mother's womb. Christ answered by explaining He was talking about a spiritual birth.
I suppose He could have, if you believe He often said things that are superfluous. Telling a person who has obviously already been born that he must be born is less then pointless.
What person who ever read that message was never born?
The only implication of this particular reading of this passage is that Jesus is somehow demarcating the unborn for special treatment. In this case, that means they can never attain salvation.
So, to sum up, Jesus was either saying something pointless (telling people they must be born) or something horrendous (excluding the unborn who die from salvation).
SD