We got some new details about the upcoming Winnie The Pooh horror film sense the property has returned to public domain from the film's director Rhys Frake-Waterfield:
"Christopher Robin is pulled away from them, and he’s not [given] them food, it’s made Pooh and Piglet’s life quite difficult. Because they’ve had to fend for themselves so much, they’ve essentially become feral. So they’ve gone back to their animal roots. They’re no longer tame: they’re like a vicious bear and pig who want to go around and try and find prey."
The original Winnie the Pooh stories recently became public domain, which is how the filmmakers are able to make this movie without being sued by Disney. However, Disney still owns the rights to the friends featured in the stories, such as Tigger, so they will not be in the movie.