Many Pixar fans were shocked when the studio announced plans to continue the Toy Story franchise with a fourth film. While many assumed that the third installment wrapped up the tale, one of Pixar's original Brain Trust says that they never really planned to be done after Toy Story 3. While Andrew Stanton, who co-wrote all of the Toy Story films so far, says they were certainly going to take their time to get Toy Story 4 right, there was always the potential for it to exist.
Nobody's harder on us [about] making a great Toy Story movie than we are. We know what it feels like to hit the bull's-eye. And that's part of the reason we've delayed it, so that we can really nail it. I know there's a lot of concern about 'why a fourth?' But the truth is, we always had the intention of continuing.
Pixar's relationship with sequels has always been a little odd. On the one hand, they have always said that there is no pressure on them, either internally, or from the larger Walt Disney Company, to produce a sequel to a movie simply because it was a success. Having said that, if we look at every film the studio has ever released, or has officially announced, the vast majority are either films that had sequels made, or are sequels themselves. Only one of the four films that Pixar has announced in the next three years, Coco is an original idea, the other three are sequels to Cars, The Incredibles, and Toy Story.
As a trilogy, the three existing Toy Story movies tell a beautiful and complete story. They're about growing up, and once Andy grows up, there isn't anything left to tell. We all assumed this was the end for the franchise, and contrary to what Andrew Stanton says to Yahoo, it doesn't appear there was "always" an intention to continue the franchise, although there were certainly indications that it might. However, it may be fair to say that Pixar did not necessarily see Toy Story 3 as the end of the series that many of us did. Instead, they were as open to there being a Toy Story 4 as they were to there being a sequel to any other Pixar movie. They'd make it if they had an idea, and eventually, they did.
Toy Story 4 will be taking even more time to get it right than we previously believed. Previously set for a 2018 release, the movie has been pushed back to 2019, with The Incredibles 2 being moved up to take the open slot on the release schedule. In the end, regardless of whether or not you believe there should be a Toy Story 4 we are eventually going to see one and so fans will simply have to hope that Pixar does what they promise and makes it great enough to be worthy of the franchise.