The problem is compounded by ROTJ as it currently stands with Luke going back to Dagobah only to have Yoda tell him those few days training were all he needed and then dropping down dead mid sentence.
"Hi Mark, I'm getting on a bit, actually I'm just about to die, oh yeah we lied to you about your dad, kill him and your a Jedi....oh by the wa..yy...your hav..e ..a ...sis..ter.........."