I'm going to put on my tin foil hat here. This is just my opinion and not any sort of truth serum to the Dylan situation.
I think the money to come Nebraska outweighed a QB battle with Stockton at Georgia.
I also wonder if NU & DR agreed for one year, as a true freshmen starter, knowing he could either stay another year or go to the portal with a year of experience.
And perhaps DR really liked it at NU, with everything, but especially since Dana started calling plays against USC, Wisconsin, Iowa and the Bowl Game fun, it made him reconsider going into the portal at that time.
Perhaps he chose to give NU a second year and the staff loved that idea. Maybe this whole time NU and Dylan was quietly a "one and done" situation that turned into 2 years. And they all sold us all into it.
And then the season fell apart, his family situation, his injury and knew he had to go.
That's my tin foil thoughts