I think The last goodbye at the train station is a promise from the opera singer that they will meet soon ,,and he won't let him go without assuring him that he can't be parted with him
the opera singer will settle his affairs with his theatre and will leave the city especially after he insulted that Japanese general ,,, the Japanese won't let him be at peace so he won't live long in the city alone without his best friend and soulmate
In the previous episodes when CFT lift to shanghai the opera singer couldn't bare to stay long without him he ran to him there ,, he would do the same I'm sure because the whole drama was about them being inseparable friends
