Perhaps but the grass on this new surface is such that the horses hooves are not penetrating the surface. Liken it to racing on glass - having a camber just changes the vector of the slipping as the hooves still won't be penetrative the surface.
I listened to Wilcox explaining how after they did the first round of remedial work the horses hooves were going in 10mm! The picture I posted doesn't show that.
The only reason they don't slip on the inside is because the surface has become rough. The wider you go on the bend the less rough it is hence more slipping.