I first saw Revenge of Revan mod 6 years ago in development at ModDB.com.
No new Demo for 6 years doesn't mean he isn't developing the mod. This mod is basically making a whole new game with lots of new content, textures, modules, NPC's, voice overs and god knows what else. It will probably contain hundreds of thousands of small scripts that would be horrendous for any other modder to actually make, and on top of all that hard work I doubt he'd want to make updates for Demo's when he could be focussing on the main mod itself. This mod for all we know might take another 6 years to make.