Ernie Hudson was busted.

Film Sometimes urban legends are true. Ernie Hudson did audition to play his Ghostbusters character Winston in the animated series but was turned down in favour of Arsenio Hall. From an AV Club interview:

"Yeah, I did, and it was funny, ’cause they said, “You don’t have to audition for the part, but the director wants to hear you read the material.” So I went in to read the material, and the guy said, “No, no, no, that’s all wrong! When Ernie Hudson did it in the movie...” And I’m like, “Well, wait a minute: I am Ernie Hudson!” [Laughs.] So when I left, they said, “No, it’s not a problem, you’re gonna do the voice.” They called me about it—I was shooting a film; I can’t remember what film I was doing—and then I never heard anything from them. Then I found out that Arsenio [Hall] was doing it. I was very busy doing other stuff, but I was really disappointed because the thought of someone else doing Winston was not something I felt great about. Arsenio’s a friend, so there’s no disrespect to him. But they had me come in and read, and even though they said I wasn’t auditioning, I dunno, I guess I was just there to have the director get on my nerves. Who knows what happened there? Whatever the case, I didn’t get the part. Unfortunately."

There's also something about his non-appearance in the publicity material. But the real story is how he was treated in the pan/scan version of the film which was the only version I watched for years.  Only when the film was released in dvd did I realise how present the character is in the film especially in master shots of when all four of the Ghostbusters are on screen. Hudson had all but been removed from some scene on VHS and television.