The idea of the first trilogy was to show the danger using biotechnology to commercial ends. To me, this chapter is closed and I've always thought that an interesting sequel would be to explore how the world has to deal with dinosaur now. The global idea would be : how the resurgence of ancient species would impact our ecosystem ?
Grant asks in Jurassik Park : "What will happen now ?". How the cohabitation will work on a larger scale ?
For the context, you can have black markets with dinos, leading to find some of them all around the world (abandonned ones, escaped ones). Some creatures could migrate by themselves on differents parts of the world, etc. With time and proliferation, we can imagine that their presence could destroy our natural balance, creating shortages in crops, return of unknown prehistoric diseases, etc. A new jurassik world to come...
What I see here is a logical continuation of the comments on commercialism that corrodes our scientific advances. The influence of mankind on the environment by its technological evolution is a very current issue and wouldn't be ironic that, metaphorically, we slowly yield our place to those who have gone before us because we failed to control our power ?
In Jurassik Park, dinosaurs were searching their place among us. In a Jurassik World, it could be the opposite.