Why is 'Ghostbusters 3' happening?

According to Digital Trends, "The Ghostbusters are coming back to the big screen, and this time around, the film will continue the story that began with the original 1984 movie." Original Ghostbusters director Ivan Reitman, told the press, “This character came to me. She was a 12-year-old girl. I didn’t know who she was or why she popped into my head, but I saw her with a proton pack in her hand. And I wrote this story. This story began to form over many years actually. It started with a girl and all of a sudden it was a family. And eventually, I knew this movie that I needed to make, that I needed to write.”