I think it is too subtle, as well. I had to slow the video down to notice the Force will-o-wisps, as they appear to me. And we’ve never seen force ghosts depicted that way, so an audience might not even pick up what they’re meant to be, exactly.
I know a subtle approach is preferred, but I think it would look cool to actually see the silhouettes of figures standing behind Rey, maybe only seeing faint glimpses of them for a few frames, whenever the lightning flashes. I mean, we can hear Qui-Gon say “We stand behind you, Rey.” Maybe they literally are.
Plus, when Palpatine stops and looks down at Rey, at first it almost looks like he is looking around Rey.