I like to read tea leaves, usually incorrectly, this is my thinking as well.Let's see, here . . . .
If they came unofficially, the weekend of April 10th, and preserved their "official" visit for a later date . . . . and they are going to announce at 4:00 p.m., Central on Friday, April 16th . . . .
That would strongly imply to me either that: (1) they are a lock for a UK commitment on the 16th;, or (2) they are completely immune from the potential awkwardness of being a UT commit when they do an official, at a later date.