It would not matter for the angel told John not to write the words down,so God does not want us to know,and if it is Paul that was caught up to paradise,and heard words that is not lawful for a person to speak,then the angel that told John not to write it down would also be unlawful for a person to speak.
2Co 12:1 It is not expedient for me doubtless to glory. I will come to visions and revelations of the Lord.
2Co 12:2 I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth
such an one caught up to the third heaven.
2Co 12:3 And I knew such a man, (whether in the body, or out of the body, I cannot tell: God knoweth
2Co 12:4 How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter.
2Co 12:5 Of such an one will I glory: yet of myself I will not glory, but in mine infirmities.
But Paul sure has a funny way of referencing himself by saying he knew a person above 14 years ago,and he was caught up to paradise,and he will glory in that person,but not glory in himself.
Paul is obviously talking about someone else,and not himself.