I think it's funny that this bothers you. If you use Utah's count, the rivalry is 55-34, or a winning percentage of 61.798% for Utah. If you use BYU's count then it's 52-31, or a winning percentage of 62.651% for Utah. We're trying to do you a favor by counting the six BYA games, as it makes your winning percentage slightly better (since we split them, 3-3).
And BYA became BYU, so it's like counting games against Texas Western College as games against UTEP. Same school, new name, new focus.