Some players like finishing off their careers with the team that drafted them so I don't think it wud be an insult to Selanne as you said.
First of all, it would be his choice to sign with the Jets if he wants so I don't think he would be insulted to play for them lol.
He's won the cup already.
Though, I wanted to see Kariya and Selanne again with the ducks but too bad he retired