Well if you go strictly by the time of day then technically, it's not, or shouldn't count. Only the 3rd game would be considered a primetime game.
Based on the term itself it's "between 7pm and 9pm when most people are watching tv" but in the sense of Thanksgiving, most people are watching all day.
Kind of like would you consider the Macy's Christmas parade primetime. I'm sure there are millions watching but it's at 10am. Who knows?