Rules for Credits

Toon: I believe those credits are ineligible, unless the person was actually credited for them on screen in the original film. As stated on the "Eligible Credits" page:

There are certain types of credits that we do not list unless they are specifically credited on-screen: these include work on marketing elements of a title (work on key art, trailers etc.), or on non-theatrical versions (e.g. DVD authoring, supplemental materials, captioning etc.), or on localized releases (dubbing, dialogue translation/editing on foreign versions etc.). We do not list these credits unless the person has received an on-screen credit for their work in the original version of the title. 

https://help.imdb.com/article/contribution/filmography-credits/eligible-credits/GFXKZE9VXLB5CR8M#