Loses the entire point of the original story and forces it into girl magically bonds with a wild horse and can somehow handle it better than people that actually are experienced.
By making Beauty a horse that was born wild you lose the point that a good home in the early years of a horses training leads to a good tempered animal and contrasting that with harsh treatment and hard work that often horses are/were subjected to. The Beauty in this story has 0 reason to behave for people who treat her badly except that it "fits the story line"