If he’s top 25 or not is a different discussion. He’s still a legend who has had one of the most successful and longest wrestling careers as a top guy. His opinions on this topic can still be valid even if you’re not a fan of his. And his opinion can change because as time goes on wrestling is constantly changing and Lesnar has been a top guy in all three of the decades he’s been actively wrestling. He still is bringing that big time feel, great matches and moments. So yes, Cena can change his mind. And even if he changed it back to Rock or Austin there isn’t a disrespectful wrong answer.
Don't bother trying to talk to him about Cena. It's like talking to a brick wall.