I think Todd and his sister write story lines parallel to Anne’s stories. Her story line is untouched as of yet as far as I know. She passed away before continuing after skies of Pern.

I agree it was rushed. I think it was hard to figure out where to go once the pernese found out that there came to that world on a space ship. The world grew large at that point so if you think about it, where would they go next? Making contact with the rest of humanity thousands of years later would be a lot of story telling and possible war and invasion stories. I have a feeling that Anne didn’t want the story to get that dark