IIRC, Kidd said that he was going to play until he was 40. I think it was him.
Not inconceivable but what kind of game will he have left and how effective will he be? He reinvented his game by developing a reliable 3-point shot but that was taken away from him when the Spurs chased him off the arc and he couldn't compensate.

He no longer has the speed or agility to be consistent defensively. He can still pass the ball though but is a growing liability defensively and offensively.