Sure is! Toy Story is a hallmark Pixar film. It pioneered the use of computer animation in feature-length movies and set the stage for many other Pixar classics.
It's possible that the team at Pixar felt that the full-length Toy Story 4 told the story completely and didn't require a short to enhance it. Or perhaps they wanted to save their creative energy for future installments or different projects altogether.
Toy Story is a Pixar production. Pixar has made a name for itself with its high-quality animations and engaging storylines, and Toy Story is a prime example of their work. It has become an iconic part of the Pixar universe.
It could be that the story of Toy Story 4 didn't lend itself well to a separate short. Or perhaps Pixar had other projects in the pipeline that took priority.