Several Scooby-Doo DTVs were originally given different names than they ended up being released with. Goblin King was originally titled Scooby-Doo and the Magic Castle; Samurai Sword was initially called Scooby-Doo! Sword of the Samurai; Abracadabra Doo startedout with the name Scooby-Doo and Whirlen Merlin's School of Magic; and lastly, Music of the Vampire originally had several names dating back to as far as 2009, including Scooby-Doo and the Circus of Vampires and Scooby-Doo! Lights! Camera! Vampire. The particularly interesting thing about that last title is that to date, Amazon lists this incorrect description for the film: "When Daphne becomes the star of a vampire film, the production is thrown into chaos by a real vampire, forcing the Scooby-Doo team to investigate who's behind this monstrous mayhem." The "Lights! Camera! Vampire!" title leads me to believe that this was an early draft of the Music of the Vampire film that was later scrapped and turned into a musical.
Here are screenshots from various resumes and LinkedIn profiles showing this information: