A lot of people here seem to have missed this part of the patch notes (emphasis mine):
Unreal trials are new versions of familiar duties, designed to challenge players who have reached the current level cap by providing an experience of similar difficulty to the original versions of these encounters at the time of their release.
It's evident that the intention is not to create just another trial which becomes easily farmable as gear levels increase. In order to consistently hit that intended experience they have to control the available item levels pretty tightly. Now, I don't know exactly what gearing point at the time of release they're aiming for; Akh Afah Amphitheatre was originally released in 2.4, and before that the very best item level was 110. In the same patch Ironworks and Augmented Ironworks gear was released, bringing the highest item level to 130. So in theory it could be anything between 95 and 130, though I think 100-110 is more likely.