Yeah, these are glitchy too.
Hartebeests are prone to Malignant Catarrhal Fever (MCF), which adds another layer of difficulty in acquiring new animals (especially with all of the ruminant restrictions) and convincing more institutions to take them on. It was pointed out in another thread that there is a Safari Park in New Jersey (Six Flags?) with black wildebeest, and there may be some on ranches in Texas. In AZA zoos, however, there is waning interest in hartebeests and wildebeests - I don't expect to see black wildebeest coming into the limelight in North America.