I have a correlation between school [performance] and on-the-job performance. I know you were probably comparing different schools, but within the same school there is definitely a difference. At my co-op job we always pulled from the same school[1], since we were on campus. We had to interview people basically every semester in order to keep up with the continual rotation. As we started dropping our GPA requirement in order to attract more people (we ended up with like a 2.5, school's co-op program required 3.0), the quality of hires significantly decreased in soft skills - self tasking, critical thinking, and creativity compared to when the GPA requirement was a 3.5.

Most hires were from their sophomore year, so they all had the same basic classes coming in and had a baseline of knowledge.

[1]There were a few exceptions, but they knew someone in our org before they interviewed