Highly unlikely any former airline pilot who took early retirement is going to be willing to return as a contract pilot. In most cases in pt121 that is not even legal. And those pilots would have to undergo at least requalification training, or redo initial indoc and sim training depending on how long they were away from flying. If I were in that situation I would definitely not return and would just enjoy fun flying and watching the airline CEO’s try to explain their way out of a situation they created themselves.