I'm banking on him not being a clone simply because it'd be an awfully awkward plot for him to be cloned and then given his previous memories. It's the same effect as bringing him back to life but feels even more contrived. (Don't get me wrong, bringing him back to life is obviously a contrived way of making a sequel.) And Karen Travis's contributions to canon are among the poorest, so I really don't want to use her as a standard for what sort of thing should go on (whether or not it can.)
"Everything I tell you is a lie. Every question I ask you is a trick. You will find no truth in me."
―Vergere to Jacen Solo