I think it would be fine with Mr. Shaw.
I don't understand the need to make the ending more "dark." It's a happy time. The suffering takes place earlier in ESB and in the rest of the movie, where a main character is frozen for a long length of time, and multiple main characters are betrayed, tortured and lose friends (and limbs!) in battle. Princess Leia is forced into a degrading costume to titillate a den of criminals. Luke has to deal with the prospect of turning into his father, or worse, his sister turning into his father, as well as his father's death.
There's no reason for an exhausting bittersweet ending when it can be just sweet. It's a drain on the audience to introduce another complication when everything is over.