You're right. Man United boss seems not ready to welcome Ronaldo anymore. Ronaldo doesn't have a good relationship with Man United management after he said something controversial during he played under Ten Hag's management. So far, Ronaldo looks happy in Saudi although he still doesn't get his target to win SPL trophy. With a good life in Saudi, Ronaldo must prefer to stay with Al Nassr than returning to Man United again.
Ronaldo had conflicts with both the club owner and the coach Ten Hag, and only Ten Hag left Manchester United, the club owner stays there. They are not welcome Cristiano Ronaldo returning to their club as a player and if we count another policy change from them, Sir Alex Ferguson is no longer welcome to their dressroom, and his ambassador role was closed too.
In performance contribution on field, Ronaldo only can provide goals, but less than 3 or 4 seasons ago, and he has nearly no contribution to proactive defense for the squad, it's double-edged risk to use this old player. Manchester United doesn't have a strong squad now to cover that weakness for Cristiano Ronaldo. A player has to play for a squad, a club, and it is not opposite like the whole squad has to serve a single star player, it's not modern football.
If Al Nassr gives a contract extension, Ronaldo will keep playing with Al Nassr. But if Al Nassr doesn't extend his contract, I think Ronaldo will return to his country and join one of the clubs there. If Sporting needs him, I think he will consider to join Sporting. But if Sporting doesn't need him, Ronaldo may join another team.
If Al Nassr gives a contract extension, Cristiano will take it but I think he hopes to receive an offer from Al Hilal. Receiving high salary is good, scoring goals is good as it's his hobby, but he wants to win titles too. In Saudi Arabia, it seems Al Hilal can help him to win many titles, not Al Nassr.