Traditionally, [Disney] hadn't employed formal writers but let the story instead be shaped by animators — but contemporary movies have more complex storylines, with multiple plotlines and characters. "When you're writing in live action, you have more ownership," Lee said at the studio as she and Buck were in the final weeks of making story changes to "Frozen" last month. "In animation, you have to let the best idea win. You're constantly killing your darlings." ...
Joe Grant co-wrote Dumbo. Bill Peet wrote and drew any number of Disney features, children's books, and perhaps most famously 101 Dalmations (with a strong assist from the book by Dodie Smith.)
Former Bing Crosby writer (and Disney assistant animator) Larry Clemmons penned a string of Disney features in the sixties and seventies. Ron Clements and John Musker co-wrote "Little Mermaid," "Aladdin" and others.
So, uh, no.
Writers have been invested in Disney features for decades. I have no idea how anyone qualifies to be a "formal writer." What, Ted Elliot and Terry Rossio (who also wrote minor items like Pirates of the Caribbean, Pirates of the Caribbean II, etc.) don't qualify as "formal writers?" What do you have to do to get a membership card?
Who are we trying to kid, here?