Yes, first few seasons all by hand, outsourcing the thousands & thousands of frames (per episode) to not only other animation studios, but studios in other countries. Same thing with cartoons from the '80's. In fact, you can see an increase or drop in quality in art in some shows based on where it was done, like "Batman: The Animated Series"
, where in one episode the Batmobiles litterally hugs a hills going over it, and the whole batmobiles warps to a curve (there are more examples).
You can watch Disney specials where they shows animators drawing each frame. And it should be noted each frame has more than one drawing, with layers.
While "The Simpsons" and "Futurama" are likely not using that even in rare instances, instead going the cheaper route, it's a safe bet animated Disney moives are still using traditional drawing (for the most part).