Dead is dead , retired is retired. They retired but not dead yet.
Sometimes, I wish they would have a second chance on the transfer market ... Those retired could be put in a pool, we could search these players. If you're interested in someone, you have to pay the transfer fee first (salary x 10) as a deposit, then that player would be put in the transfer market for 72 hours (BB choose the time to put that player in the market, or randomly). If no one make a higher bid than you, the retired player could be yours.
I remember Michael Jordan was in No. 45 when he came out of retirement. When he came out of retirement at the second time, he played for Washington.