Who Do Colleges Notify First?

Do they notify those accepted or those denied?

It depends on the school. Some send acceptances first, others do it all at once

Since many schools use online notification, it’s simply a keystroke to upload the decisions and allow all the applicants to see the answers.

Don’t try to read something into this

those rejected will be notified 2.3212 seconds before accepted
source: admissions officer

So for say, UMASS Amherst, they update their applicant status online overnight? but people are already finding out if they were accepted, but others still haven’t? what does this mean?