Tyson does not retire. I think he's just messing with Haye. Yesterday he called out Wilder. And why should he retire if he has a dream to become World Heavyweight Champion.
From what i've heard this is legit and he has announced his retirement and means it. He's had a good career and got some good wins under his belt, doubt he was ever going to be World Champion so retirement is probably a good move longterm for his health and family.
Added up his leftover training expense money for Haye, saw he could afford a new caravan. Why keep fighting?