He said some things on his channel that Playtonic felt they didn't want to be associated with, so they cut his voice acting role from the game. If you're an actual Anonymous activist, I presume you have the internet skills to search this forum for the already-closed discussion on this. Long story short, some people felt it was the right step, because what he said was racist and as a studio, Playtonic can choose to not include someone's contribution in the final product (you wouldn't expect some extra actor to successfully sue a movie company to leave his scene in, would you?). Others said they shouldn't have done it, and assumed it wasn't so much Playtonic's own decision, but evil social justice warriors spoiling all the fun.
Now this thread can get closed, too. Hooray.