Differentiation? Taking care of their own elites? United had exception routes for a reason. Same reason why Delta had elevated (but not branded as DeltaOne) first class service on long haul routes to SEA until earlier this spring. It was to differentiate themselves from AS who they were comepting with.

I feel like the elimination of exception routes is just a broad sweeping policy change that didn't take the small details into account.

Of course, only United has the numbers, and we're all just guessing.