Same here and there's a reason for that. Yearbooks are full of pictures of class events, etc. You would want to capture as many senior year photos as possible.
In those days, there was a 6-8 week waiting period between the final submissions to the year book publisher and the delivery of the finished books. I know this because I was on the yearbook committee when my high school class graduated in 1980.
So in order to have the yearbooks ready by Christmas, you would have had a cut-off around mid-October - pretty much skipping the entire senior year. You wouldn't even be able to publish the school's football team results in the yearbook!
That just does not make sense.
Our yearbooks came out around the middle of May and as a result, the last photos taken of our class was around the end of March.
You’re right, but see post 55 above. It seems this was not a school yearbook.