That really isn't the only reason.The is a dumb response actually. When you are playing a season after they made a black alliance and one of the players you are playing against is saying she won't put up black players. You have to address it and work your way through it. Try and figure out if there is another alliance that is the same as last year. So when someone brings it up, they are now racist? Thats ridiculous.
But yeah just suggesting there be an all white alliance in order to take out all the POC because he is afraid of an all POC alliance is a little weird and obviously the whole house thinks so as well.
I think if you look at this language throughout the game you will see he has called POC scary, bullies, etc. But hasn't said anything like that about the white players.
Also, thinking it will happen again, shows he completely lacks an understanding of what the cookout was doing. They only did it to guarantee that a black player would win in order to flip things on how BB usually turns out, i.e. the black players all going out early, and make history with the only black winner of BB. That was accomplished last year. And as they said, it was to the detriment of their own personal game. They accomplished what they wanted to accomplish. There is no reason to do it again.