Both characters suffered, but in my opinion, Anson Williams moreso.
They really did not seem to know what to do with him without Ron and Donny's characters to play off of. No wonder why Anson said that the magic was gone when they left.
In a way, though, Goodfriend's character got a boost. She got promoted to full cast member status and because of the wedding and childbirth, had a reason to interact with the Cunninghams, who were now her family.
And the reason Richie didn't make the wedding was because Ron Howard left the show! I always thought Fonzie standing in for Richie was lame. They should have waited until Ron returned in the final season and had their marriage and move to California as the plot line for the show.
"Sunday has been cancelled due to lack of interest. That is all."