This might be a deliberate decision to turn it off for a while, because it would have been insane for people to reach maps with 4-5 tier 16s. (It usually drops from Invasion Bosses with a high drop rate)
However there are people in maps now, and none for trade at all. Usually by league start + 6 hours, there's a couple dozen for trade from diviner's boxes.
External link →I double checked this and there was a change to The Price of Protection for the event - the minimum level for the card is now 80. Seems that the reason for this is that there was going to be an abundance of them, too much for a non-voided event. There are still more than you'd get from the core game but now not so many that it would be problematic. Sorry that this was not publicly noted sooner!
devtrackers.gg