The latest reports is that It has not been reopened.
The Pixar Play Zone was a pilot experience that opened on April 13, 2018 to see if they could bring back the service., Initially it was in a space near the Elevators to California Grill near the Conference center space.
Then it was moved to the 4th floor in the Arcade space which was centrally located. Most of the games machines were removed but a small subset were left as part of the Pixar Play Zone pilot experience.
Guests that tried the service reported that they liked it but it did close in March 30, 2019 very quietly and the Arcade was reopened and some additional game machines were re-added but as
@drquest posted above the prize tickets and prizes sadly did not return.
Dave