I would be surprised if the ending of Toy Story 4 was extremely dependant on the human/toy relationship. I mean, that's always going to be a part of these films by their very nature, but the ending of 3 feels lIke they closed the book on the traditional version of that.
I'm guessing whatever happens at the end of 4 is going to be largely about the toys' relationship with each other. Toy Story 3 kinda felt like a transitory film that finished 2's story and themes, but got into the kind of world toys would build for each other. A strong emphasis on togetherness in that film. Whatever happens in 4 is still going to be related to humans in some way... But I would expect a kind of ending, for example, about Woody sacrificing his life for Buzz and Jessie, rather than a human character.
I'm guessing whatever happens at the end of 4 is going to be largely about the toys' relationship with each other. Toy Story 3 kinda felt like a transitory film that finished 2's story and themes, but got into the kind of world toys would build for each other. A strong emphasis on togetherness in that film. Whatever happens in 4 is still going to be related to humans in some way... But I would expect a kind of ending, for example, about Woody sacrificing his life for Buzz and Jessie, rather than a human character.