You couldn't be more wrong. Cite me one link that refers to the '79 Fiesta as a major bowl. Just one. I even cited you a reference that said that there were only four Major bowls (Cotton, Rose, Orange and Sugar) before the Fiesta set up a national championship game in 1987. No major bowl game was played on Christmas day as was the 1979 Fiesta Bowl.
On top of which, Pitt was ranked 10th going into the '79 Fiesta Bowl, Arizona was unranked. So much for your two top 15 teams argument which was totally superfluous to the definition of a major bowl game.
Feel free to look at how the bowl games are differentiated. The FOUR major bowl games and the rest are OTHER bowl games. But please persist in being wrong.
en.m.wikipedia.org