I'd have to go back and search the PTS forum, but I believe one of my comments on the Tome over there was that rerolling could produce duplicate weekly challenges and I wasn't sure whether that was intended behavior or not. My experience with the first week's challenges on the live Tome was much the same, but a different effect. I rerolled the first "kill <dungeon boss>" challenge (there were two different ones showing) and got a new challenge to go kill the other dungeon boss (now showing twice). I rerolled it again, got something else, and moved on to the second. When I rerolled that one, it gave me the challenge to kill the first dungeon boss again, and then gave me the challenge to kill the second again when I rerolled it. The last reroll produced something more satisfactory, but that burned all five of my rerolls for the week. You'd think there would be a check in there somewhere to the effect of "player said they did not want this challenge, so remove it from the pool for the week" as two of those rerolls were used on challenges I'd already refused once.
I'm fresh out of outrage, but I could muster up some amused annoyance if required.