Actually, there was real discussion about this very subject.
Back in ‘99 there were plans to release the DVDs simultaneously with a 15th anniversary re-release of the original.
Then there were possible plans to release a Ghostbusters 3 right after.
As you know, this never happened, although there’s still chance for a 20th anniversary edition in 2004.
One way of putting it: 1999 was supposed to be the “year of the ghostbuster.” But it never was.
This stuff can be found on an article on this site, I can't remember where or which one, so you'll have to do some searching around.
Alright, I'm done.