So now we know JJ was probably pretty confident that Hamill would keep an secret. And maybe there was also the poetic temptation that Hamill could sit on another big twist for this generation’s version of Star Wars, just as he did for Empire.*
But yeah, Hamill didn’t even tell his wife about the now famous line change. Which so far gives him a step up on J.K Rowling’s lawyers. To put the clip in context, they caught him on the set Star Citizen. So don’t hyperventilate over the fact he’s in a mo-cap suit.
*(As a Gen Xer, I admit, this is my true source of cynicism. In their 30’s both the Baby Boomers and Millennials will probably have gotten /will get better Star Wars films than I did. )