Narrative endings are very difficult to craft from a writer's perspective because usually a writer comes up with several ways to end a story, but it's a struggle to find the one most fitting to tie up the plot, bring the message home, and make an impact on the audience. Toy Story 4 would have received a widely different reaction if they had gone for this alternative ending.
The film's director, Josh Cooley, seems to acknowledge this in the brief commentary which leads off the clip. "Finding the ending of a movie is extremely hard," he says, demonstrating his complete mastery of understatement. "Especially a Toy Story film, where you want it to be really impactful and really emotional. This one came pretty close."
(Image credit: Disney, Pixar; IMDb)