OB1
Jedi Master
Maybe it's there to test if the monsters need anything extra to make up for the loss of crits? From what I've seen in play, I'd say lower CR monsters don't need any help, but I can't speak intelligently on higher CR monsters. I will say that the new style of monsters post MotM may have been built with this new rule in mind.This is why playtesting the no-crits rule without those things is pointless. It shouldn't even be in the UA.
But the other thing I've realized by tracking crits and lost crit damage over the 5 encounters I've tested so far is that adding crit damage to DPR calculations is worthless. Crits are too random to have a predictable effect on the outcome of any one encounter.