Cynde Lewis cheered 76, 77
Suzette Russell cheered 77, 78, 79
Suzie Holub 76
Debbie Wagener 76, 77, 78
Syndy Garza 77, 78, 79
If what your saying about Syndy is true, then Suzette should not have been featured in the photo as well, she also didn't start until 1977.
I think the common element here is 1977. Even though Suzie Holub only cheered in 76, I think she was still around possibly early into the 77 season. The question comes down to when was the photo session took place, and when the next season's squad was chosen.
I do remember reading that the DCC auditions were closed and by invitation only up until a certain point, but I don't remember what year that was. I'll have to check. But that might explain the timeline and the Cheerleaders in the poster.