I hate when schools don't reject me after they have sent out their first round of offers! I am likely a rejection so I wish they would just tell me so! ha
I could be wrong....but it could also be the case that people could reject their offers and they will make others...sometimes I think that is why schools don't reject some people right away after they invite their initial group to the visit day....I would look at it as a likely rejection and then hopefully, be surprised.
I have just gotten an email from the graduate administrator/ DGS or a letter in the mail. 2 of them were offers with full tution remission + stipends without POI contact! The other, I am waiting on funding news. Hope this makes you feel a bit better.