In my opinion, it's a rumor that will never come true, so just ignore it.
Ronaldo will not return to Manchester United just to prove that Ten Hag is a coach who has made mistakes in his career. He didn't have a great season with Ten Hag and that can't be denied, but Ronaldo is a great player. In the SPL, Ronaldo shone and he seemed happy to be there instead of returning to Europe.
Agree. It is very unlikely for Ronaldo to return to an United. Ronaldo doesn't need to return to Man United, it is already proven that Ten Hag has made mistakes already. If Ten Hag didn't make mistakes, he will stay in Man United a longer time. I am also doubtful that the new coach wants an old player like Ronaldo. Ronaldo is no longer in his prime age to play with Man United.
Yes, Ronaldo is always a great player whatever his season with Ten Hag in Man United. Ronaldo first season with Ten Hag was also quite successful, he became the most productive player at that time. It has proven that Ronaldo actually still played well if he was given enough time to play.