pba is absolutely correct, Jothar. Last year someone from my Yeshiva (which I graduated in 1993!) wanted to know the entire class list since pre 1A! He would like to make a special Alumni melave malka. I told him sorry buddy you’re a tad late. y’know, juuuust missed it, by about,say,….2 decades!!!!!
From graduation, the yeshiva better keep tabs on each student and continue to keep some sort of kesher. You can’t come back 20 years later! I don’t even feel like it was my yeshiva anymore. They messed up, big time!