Collaboration Among Admissions Offices?

One of my kids applied to 5 schools considered among the more selective/prestigious and got into all 5. And this was the 2nd kid who had the older sibling’s school among the ones applied to. I don’t think they collude.

A sizable percentage of applications don’t qualify for FA, so…

Many of the feeder private middle schools do this as well with an aim to getting better matriculation for their whole class of graduates.