As an aside, has anyone ever noticed the inordinate number of "stand alone" heads featured in the 8th series? That is, heads that aren't connected to a body? (Like the teacher's head and boy's head in "Gadzooka.") You find a few examples of this here and there, particularly in the 1st and 2nd series, but Series 8 takes the record.
"Dr. Popper" - the head has popped off the body
"Hostile Thinkies" - there's just those two weird blue and green heads
"Hopeless Snowballs" a snowball is striking a "floating" head
"Kentucky Fried Fingers" - the Colonel's head isn't connected to anything
"Burpsi-Cola" - again showing the dangers of gassy soft drinks
"Kleenaxe Tissues" - no comment necessary
"Rolaches" - no body
"Smoocher's Jam" - no lovers' bodies
"Scary Lee" - no vampire's body
Several other parodies primarily show heads as well, with very little body showing: "Knots," "Daffy," "Scorch, "Cheep," "Choke-Up," "Bone Ami" (the skull,) "Yikes," and "Ivery Snow." Even in "Kong Fu," the ape is giving a karate chop to a very shadowed neck.
When you find this much of something going on, what might have been considered coincidence instead begins to point toward obsession. Perhaps someone gave Jay and/or Norm a head's up that their heads might be on the chopping block and this was their way of trying to head things off?