I'm guessing they don't want us to avoid unlocking the new dungeons so we get to roulette the arguably easier old dungeons. This happened before in 2.2 I think. People were advised everywhere to not unlock the new dungeons and just have easy roulettes with only the good old Wanderer's Palace etc.

In that case I think it's perfectly reasonable.

Besides, is it actually not possible to cap without the expert roulette? I've not calculated as I've just came back after a long hiatus. If you can cap without the expert roulette, then I don't see this as a really big problem.