Swamp and left of MoD as well? I don't recall these areas being disabled.
Since zombies were added to candy hunting PK has been disabled for the overworld, or at least should have been. It's how it was originally designed and implemented but I haven't been very active the last couple Halloween's so if it was broken I doubt anyone noticed.
A good thing about this is that these military wars tend to be very laggy, and Halloween is also pretty laggy so we don't get a combination of those two things colliding.