Disclaimer: I'm not super familiar with DUST PF.
That being said, for Dusties, I don't see why it wouldn't be, at least in some places. If nothing else, outside the Empires, most things are legal because there are very few laws. Given the tech Dusties seem to have access to, it would in fact surprise me if they didn't have something like this. In some parts of the cluster (Delve comes to mind) bloodsports are probably held with slaves already.
It's a little different for podders, because the cloning tech involved is a bit different. Outside the pod, the only cloning tech they have access to is the (sometimes controversial) soft clone, which is not nearly as useful as a Duster style clone. So probably not, for them.