I just remembered this. It was back in 1997 and I picked up this woman's magazine that belonged to one of my aunts because it mentioned it had an interview with Sigourney Weaver in it.
I had kind of forgotten the GB movies at that time and think I was reading it hoping for some news on Alien Resurrection.
Anyway, I read that Sigourney Weaver makes up her own Ghostbusters stories to tell her daughter. She also brought up GB3 and says she made up her own sequel story to tell her. All she mentioned about it was it had “moving walls”.
It's not really GB3 news, plus it's a bit old, but at least we know Sigourney still has an interest in the movies and would likely be on board for a third. Just thought it might interest some of you.