If I check the Custom Delivery allowances in the Timers menu. As of patch day yesterday, it showed 12 allowances.
My first reaction was; great they increased it. I then proceeded to gather 12 of the required item (Ice Stalagmites)

Then when I returned to Zhloe in Idyllshire and was only able to turn in 6 of them. My timers still list 6 available custom deliveries.
I then proceeded to Rhalgar's Reach but no one there has any quest markers beyond MSQ.

I did text search of the 4.1 patch notes and found only 5 instances of "custom deliveries"; none of which mention anything about it.