I too have never heard of a reduced change fee on Ted. I can remember some discussion of a cap on one way fares and a simplified fare structure, but nothing about a reduced change fee.

Lots of flyers on this board on unhappy with Ted's lack of first class, among other things, so you are not alone in your view. Unfortunately, all LAS flights are Ted, so there isn't much choice if you want to fly UA. If you are flying IAD-LAS in the future and upgrading is important, you might want to consider routing IAD-LAX-LAS or IAD-SFO-LAS, as with both these routings you will be able to sit in first class for most of the way.