I'm thinking that American Tale is probably animated at 1.33:1. I haven't seen it recently, but I don't think Stephen Speilburg would release it non OAR.
Regarding the list, a new one is coming soon, that will be updated regularly.
Well, in a lot of films, even though they're open matte, they still crop the sides a little.
A good example is Cruel Intentions. The wide version is matted, but on the sides of the frame, a bit extra is definitely noticable.
So open-matte doesn't mean completely open-matte... some image is lost, so cropping it to 16:9 on a 16:9 set isn't going to completely fix the problem.