What do schools know about our posts?

Back a long time ago (when my daughter HS 2012 was applying), a few schools had an adcom who was active on their college’s page. They clearly represented themselves as such. They were helpful answering questions about the school (what programs are offered, deadlines, requirements, etc.). Tufts comes to mind as one. At the time, that adcom also wrote an admissions blog on the school’s website. Don’t know if any schools still do this.