Hmmm…honestly, I think I prefer it without the sound. Just like how the music drops out at that point, I think the line has more weight when there’s nothing to distract from it.
I agree, the sound effect really seems to contest for attention over the climactic line, and at that point in the scene it feels odd to hear the sabre ignite and not see it. Like, if it was intended to be there originally, it would’ve been a medium shot that shows Rey igniting the sabre. Instead it’s a closeup of Rey’s face because we’re only supposed to focus on what she’s saying.
Personally I really liked the mockup some pages back that places the ignition sound as Rey swings the saber, that seemed to fit a lot more naturally to the scene, and it actually gives more punch to that moment instead of clashing with it.