There was a massive missed opportunity to have R2 tell all the stories of their adventures to 3PO in the final scenes. Can you imagine how cute/heartbreaking that would be?? aaghh
It wouldn’t be impossible to insert 3PO and R2 into that last shot with Rey, or even have them wandering the desert themselves after the Rey bit (utilizing scenes from the original Star Wars could be fun here), and have 3PO ask the question, and R2 just beeps. 3PO responds with something like “Oh, my. How long ago?”, and R2 beeps again. “How old AM I?”
And have the conversation fade, with maybe a line from 3PO indicating R2 is recounting the podrace or some event from Episode I.
I actually just got chills thinking about that.