Wow, you're going to give them a full three years.
One thing: Each studio only produces, on average, one movie per year. And they only really usually announce the next year's movie, not the ones coming out two or three years later.
So, after DAS does four non-sequel movies in a row, you're going to complain about Frozen 3 and Zootopia 2 which is only over the next 2 years, not three?
And after Pixar does 5 non-sequel movies in four years, you're complaining about the next 3 years... and what movies will that be? Elio and Inside Out 2.
Over the history of Pixar, in general, one of every three movies has been a sequel. Nothing's changing that we can see because we don't have their 3 year plan.