IMO, Nicodemus's non-enlightenment should not affect the correct rendering of Christ's intent with the word 'anothen' here. Anothen ( from above, from a higher place, of things which come from heaven or God, from the first, from the beginning, from the very first, anew, over again) can mean 'anew' or 'over again', but that's not what Christ meant, thus His further explanation in the next verse:
5 Jesus answered, `Verily, verily, I say to thee, If any one may not be born of water, and the Spirit, he is not able to enter into the reign of God;
6 that which hath been born of the flesh is flesh, and that which hath been born of the Spirit is spirit. Jn 1 YLT
Christ wasn't speaking of an earthly physical birth which Nicodemus wrongly perceived, He was speaking of a spiritual birth FROM ABOVE.
Just wondering about your thinking that Nicodemus was in some non-enlightened state.
Would you agree that in John 3 it seems the Holy Spirit has been impressing upon him the need to get answers he sought? Why would he seek out the Master unless the Holy Spirit were impressing upon him he need?
Later, was he not one who cared for the body, perhaps providing his own unused burial chamber (thou there is no documentation).
Wouldn’t it be remarkable for Nicodemus to know he would one day lay on the very spot from which the King arose?
Perhaps I am mistaken, but is not Nicodemus responding to the light he is given, and therefore actually enlightened?