It doesn't matter if chantal is racist or not, or whether she intended charlie "coal" to be a slur or not. She makes her living showing snippets of her life to the public. I'm sure many bloggers, chefs, youtubers, singers, athletes, business people, etc. are wildly bigoted, ones we'd never suspect. But we'll never know because they consider what they're putting out for public consumption. They probably check and recheck anything they say about people who are in groups they may use slurs against in their private lives. Those people probably would have gone with charlie gold plated, because she's fake, or charlie scrap metal, charlie green because she's a jealous haydur.
Most people who aren't racist, or don't use racial slurs in their regular lives, not even to be edgy, wouldn't need to think twice. They'd know charlie coal was as bad a look as charlie tar.
I don't know if chantal is racist, but it doesn't matter because her primary crimes are stupidity and arrogance. She's too stupid to manage her brand or come up even slightly plausible reasons why charlie coal was an innocent mistake - for instance, she could have said she got her metaphors mixed up and was thinking about diamonds and them being formed from coal (they're not, but most people still think so), thus it made sense to her that coal was the opposite, she just mixed up gold and diamonds. She's so stupid, I'd fully believe that's what happened. Second crime is she's too arrogant to apologize for the sake of her brand. No, she just stupidly and arrogantly doubles down. Racism is a branch of stupidity, but the stupidity comes first.