Author Existence Failure: Not strictly related to Birdwell, but the reason the animated series was spun off to Clifford's Puppy Days and the main show was abandoned was because of Ritter's untimely passing.
Over a decade before Emily Elizabeth was an irritating magnificent bitch, she hung out with Beetlejuice on a big, comfy couch. Because, prior to Grey DeLisle picking up the role, Emily Elizabeth was voiced by...
No Export for You: The iPhone and iPad game are this to South America and Asia, as are the releases on the Leapfrog consoles. Most of the toys, however, are North America only, especially those that are not made by Scholastic themselves.
The Other Darrin: They did not replace any of the characters on the the show in the strictest sense, but in the original 80s specials, Emily Elizabeth was voiced by Alyson Court. On the 2000s series, she was voiced by Grey De Lisle. Possibly also Lampshaded by the fact that both had a vastly different art style from each other.
Outlived Its Creator: Norman Bridwell passed away on December 12th, 2014. At this point the TV show has stopped and has had no new episodes since 2005, but he has two books that is still unpublished. Also, the movie won't be released until 2016.
Recursive Adaptation: Inevitable. Books that were based on the TV show were published once the show became popular. Given that the show is based on books in the first place, yeah.