There is another angle as to why there has been no announcement yet that nobody has brought up and it is this.....
Nebraska and 1890 aren't done milking the cow yet. Why have him commit when the $$$ donations are still pouring in? The pace of donations has been accelerated by the mere mention of DR and cash is arriving from all corners. The brakes get hit in a big way if we make it official that we have our man. Keep the fan base on edge and engaged up until the last moment (Wednesday) so that they can squeeze every dime out of regular Joes.
Side note: What area of American life doesn't feature people just being absolutely soaked for cash donations these days? I know for a fact lots of you get solicitations hourly from one entity or another.