All that stuff could have happened months before afterlife or in 1993. If we assume it's recent, they could go anywhere with GB4.
It's hard to believe people want a Ghostbusters 4 with just Phoebe, Trevor and Lucky and not what happened to the original Ghostbusters.
The OG's are done. Jason isn't going to go into that well again when it could be in animated form, or done by IDW. The only OG's we will get for certain are either Dan, or Ernie and that's not a hundred percent guranteed.
Most of us would love to see a whole movie centered around the original cast but it's just not in the cards. They are more then senior citizens now. They won't be bustin a move, they'll be bustin a hip if you get my meaning. Ernie seems to be the only OG that's in good shape for his age.
(Again i'm not saying anything bad about the OG's, it's just a fact of life.)
Jason passed the torch without killing anyone off and litteraly brought back the dead. I'm glad we have them as support for the new cast.