Years ago I remember reading online that allegedly The Black Cauldron was supposed to be released to video in the Spring of 1990, but was instead replaced in the schedule with The Little Mermaid.
The timeline fits with this reissue, and it makes sense when you realize that Disney at first was reluctant to put out its animated movies to video shortly after their theatrical run. Both The Great Mouse Detective and Oliver and Company would have to wait several years to get a home video release, even though they debuted in theaters after the advent of WDHV's direct to consumer releases of Robin Hood, Pinocchio and others. Little Mermaid's box office and merchandise sales were what prompted its speedy release to video.
After that there was no rush to get Black Cauldron released. It was simply not a priority after newer, higher grossing movies like Aladdin. Its eventual release in 1998 was encouraged thanks to letter writing and online campaigns by Disney fans who wanted to complete their collection and now had access to more information about the film's existence. I read it sold 4 million tapes, which compared to the 20+ million Snow White and Lion King sold was considered a disappointment, but in hindsight that was pretty good at around $25 a copy. Not bad for their then biggest animated flop.
