Possible Bug: Event Opponent PW Pool

Corn_Noodles

In the current Terrors event, it is possible to play against mono-colored planeswalkers that do not share a color with a node. Previously, this was not observed happening. For example, Koth and Ob Nixilis are possible opponent PWs in this event, but red and black are not valid node choices. Is this a bug or is this an intended change?