Here's why I think it's Auburn:
Their class is shaping up quickly, and they're looking to take 3 backs. They now have 2 committed with Barber flipping last night. That leaves one spot open going into Signing Day, and with all the rumors of a possible Folston flip, Ford can guarantee his spot in the Auburn class if he commits today. If he waits until the 6th and Folston flips, he's lost any chance at going to Auburn.
Meanwhile at Tennessee, Ford could wait until the 6th (as he's planned to do all along) and not have the slightest worry about losing his spot in UT's class. So if he were favoring Tennessee, it wouldn't make sense to suddenly alter your scheduled announcement two days before it happens.