AGAIN...
Starbonds are used to measure how much "star power" a performer (or director) brings to a project.
Starbonds get attached to projects when they are listed on the project's official website; named and/or pictured on the poster; included in the press kit; casting announced in the trades (because later on they will likely be added to the official website; credited before the movie; named/pictured on the poster); credits appear before the movie or after the movie before the rolling credits.
HSX does not usually credit starbonds for cameo roles (unless they meet one of the criteria above). Cameo roles are not usually done to get people into the theater... they are usually done to suprise people who are already in the theater watching the movie.
What about Jonah Hill in HAILC?
"HSX does not usually credit starbonds for cameo roles (unless they meet one of the criteria above)"
"Starbonds get attached to projects when they are listed on the project's official website; named and/or pictured on the poster;..."

Jonah Hill is listed and pictured on the movie poster = credited.
I do not know exactly why BCUMB was credited to Zoolander 2, but he was featured in the trailer (which usually does not get an attachment) and he had a cameo sized part (which usually does not get an attachment) but my best guess was that his appearance in the trailer ended up causing a backlash against the movie which made the movie more widely known to more people, more people knew he was in the movie and came to see the movie to see what else his character might be doing.