Questions like these are hard to determine, similar to when they started to use multiple dings for a correct guess on Lucky $even and Any Number, which happened at about the same time. It was definitely after they introduced the next set at the end of 1989.
Another question regarding verbiage is when Bob would introduce the rules involving the 0's and numbers higher than 6. Originally, he would wait until after the first roll (provided it wasn't in the price) to explain to the contestant by saying "Let me tell you that there are no numbers higher than 6, and there are no 0's in the price." Eventually, Bob would always explain that rule at the start of the game. From what we've seen on Pluto, both instances of this description have been seen, but probably around the time Rod began announcing, the explanation at the start of the game became permanent. Perhaps due to situations like the playing you just saw may have influenced Bob to always explain before the contestant got too involved into the game. I just watched a Kennedy episode and he made the higher than 6/0 rule spiel at the start of the game, while he simply just said "but" after a contestant rolled a 6, assuming she knew the rule.
