The episode was originally positioned between My Manhood and My Dumb Luck.
Due to the writers strike, the season was cut short and the executives had probably chose this episode for a decent finale...that's why the continuity problem.
My Manhood: Turk loses a nut
My Princess: Kelso still chief and comment made about Turk having only one nut.
My Dumb Luck: Kelso quits