Do the four current films set in the "Jurassic Park Universe" share the same canon universe?
For the first three films (Jurassic Park, The Lost World: Jurassic Park, and Jurassic Park III) I think this is indeed a "YES" because we see many of the same characters (Dr. Grant, Ian Malcolm, etc.).
However, the fourth film Jurassic World, seems to be a reboot of the franchise. While we do have some of the history (the park was John Hammond's vision), a recurring character (Dr. Wu), and the original park's ruins these could just be homage to the original series.
An interesting note from an out-of-universe perspective is that the author of the original Jurassic Park novel, Michael Crichton, passed away in 2008. I do not know how involved he was the making of the first three films, but he was alive during that time at least.
It it stated in any advertising materials, interviews, or elsewhere that all four films share the same canon?