Why are they ignoring part 2?
What does it have to do with this story? Like how if those events had taken place would they influence this one?
I understand that part 1 is like lightning in a bottle, but I consider part 2 to be an above average sequel for being made in the 80s when a lot of sequels were just rehashed versions of their original... GB2 had original villains and kept expanding their "universe".
My favorite line out of part 2 is: SUCK IN THE GUT GUYS WE ARE THE GHOSTBUSTERS!
*Edit, Jason Reitman was asked this question and came out with a somewhat bs answer that they are not ignoring part 2 just that "...nobody knows Ghostbusters 2 outside of Vigo the Carpathian and the Ghostbusters II logo."