if ronaldo moves from MU to chelsea, PSG or bayern then he is no longer worthy of being called a MU legend. many people criticize and support whatever he does, but he must realize that the team that first raised his name was MU. if Ronaldo retires at MU then he deserves a MU legend but if next year's transfer market he moves to another club, then he is not a MU legend.
What is the size of a player if he wants to become a legend on a team then he has to retire on that team? lol.
The player has the freedom where he will retire, whether it's the team that raised his name or any team that might be the eternal rival of the team that raised him. If you say so, then don't forget Sporting where the team was the team that started his football career. Whether or not he has been named a Manchester United legend, he is one of the players who has been part of the success of Manchester United in the past.