> Either it's CC-BY-SA or it isn't.

Or it's dual-licenced... As I read the comment you are responding to, one could pick the license they like. If they pick CC-BY-SA, then they will have to share-alike and provide attribution, but it's allowed in commercial projects. If they want to use it in a non-commercial project, then they can use the T&C license and don't need to provide attribution.

I am not a lawyer, but I've seen dual-licensed projects before. Please do correct me if I'm wrong about this though.