It was more that most of those stories are in the public domain and can be freely used. They all have European settings in the original tale and Disney didn't change it for US audiences which makes it more authentic, especially if you've read the stories.
As far as the two listed that aren't...
I'm greedy... I want them all... even their lesser films. Hopefully A Day at the Races will be coming soon and the last 4 will at least receive double-feature BR releases like was done with the DVDs.