This is correct; the predictions have been updated based on the most recent data. As you indicated, the biggest changes will come from institutions where we had little data previously.
Getting the new predictions out was our first push; next, we will be working on providing additional information and functionality around the predictions to help give people a better idea of what the predictions mean, to reduce the confusion around what happens when the predictions change, and to give people more control over when their predictions update.
Normally the predictions won't change, even if our models change, without some element of a profile changing. Kevinbr1212, if you can reply with the names of some schools whose predictions changed, I can take a look and see why this might have happened.
Well the change from 80% to 20% for many of the schools did appear to be a glitch since they now loom around the high 60%. None of my data has changed, but if you still want to look at it my chances for UPenn, Columbia, Duke, and Washington U went down around 15%. For example UPenn, regular decision stood around 81%, and post-update now stands at 67%. I'm not complaining about the change or anything, I was simply confused on why and how the percentages changed.
Aside from that topic, I wanted to ask if the data you guys channeled back into the system was attained from users like myself or from applications from the actual colleges/universities?