It's a big deal that Jontron is a white supremacist and he voices a character in the game. End of. Whether or not the role is tiny or big, whether he speaks in english or gibberish. If you're ok with a white supremacist being a voice in your game, just say it. White supremacy isn't a differing political opinion either, it's hate speech. Just like you wouldn't have a hate speech spewing radical Islamic cleric voice a character in something no matter if he is grunting gibberish.
If the character or game are preaching hate speech or if jon tron had been hired to do the cameo voice AFTER he revealed himself as a piece of shit bigot, i would totally ask his participation to be removed, but come on people, put in some context in the events, Jon Tron's contribution to the game is yelling nonsense like "eekum bokuum", you won't even be able to tell which character is using his mumble and he was hired (and likely recorded his lines) sometime around 2015, playtonic can't fucking see the future to predict this was who JT would turn out to be.
This isn't supporting, say, Mel Gibson's antisemitic drunk ass by watching his movies, this is like wanting to boycott star wars because the guy wearing the Ewok #21 costume turned out to be a racist.
It's a really weird idea to want to hurt so much the people at Playtonic over something they couldn't possibly had control over, JT did all this shit way after the game already had gone gold.