I think that its the same Joey.

U r right about Its my life not saying "and they lived happily ever after", but it would be hard to actually give them an ending like that, in that song, because the message was all about living your life to the fullest.

I think Jon probably decided to right one more happy song about them, and say that it is the end of the tommy and gina chapter.

I rate they get Sahara Jack and Suntan Sally going for a song! (a fun song of course)