Dating a black guy with internalized racism ??

All right, so I have to ask this question on behalf of my friends, but also myself, based on my friend’s situation.

Last year, I became friends with this guy. Let’s call him M. He’s dark-skinned, and we started talking strictly as friends. My friend, who we’ll call L, and I eventually made a group chat with M. M then added his friend C, who is light-skinned.
In the group chat, M and C started saying really nasty things about Black girls. They talked about how Black girls weren’t their type, made negative comments about darker-skinned women, and talked about how they preferred Latinas, Asian girls, and other races. I thought it was weird, so over time, I stopped interacting with the group chat, although I remained friends with L.
L continued talking to M and C. Eventually, both M and C tried to make a move on her. She’s brown-skinned and Black, which is literally the type of girl they had repeatedly said they weren’t attracted to.

Recently, L told me that she had been talking to C. I was like, “Girl, why are you talking to C when you know this man has said so many disrespectful things about Black women?”
And it wasn’t just the things they said about Black women. In the group chat, they would also send pictures of girls they were talking to and make disrespectful comments about them, talk about how they weren’t serious about those girls, and generally speak about women in a really degrading way.

So I genuinely don’t understand why L would want to talk to C, especially knowing all of that. When I brought it up, she said, “I can fix him,” and that it “wasn’t that bad.”

At this point, I feel like she’s a lost cause, but I need to know if I’m overreacting. I tried talking to someone else about it, and they said that maybe M and C didn’t actually mean what they said and were just contradicting themselves. But I don’t really agree with that because, when we were all friends and talking in the group chat, none of it came across as a joke. They genuinely seemed to mean what they were saying.
So am I overreacting, or is it reasonable for me to be concerned about her talking to someone who has openly said those things?