A lot of schools crow that [insert number above 90 here] percent of their students were accepted at a four-year college. Getting accepted to college is definitely one step better than just graduating high school, unless we are talking about open admissions schools, in which case an acceptance letter is no greater signifier than a diploma (unless it is paired with a completed FAFSA and registration for the fall semester).
I assume that some places that use acceptance as a milestone have internal research showing whether their students actually matriculate and succeed in college. I hear the data coming back is not always great. It is good to celebrate levels of accomplishment exceeding what was previously attained, but journalists (and researchers) need to ask what happens next.