he just says it’s primarily about sacrifice
But it’s not.
It’s not because ultimately it’s not really primarily about anything
I’d say it’s a movie about learning to work together despite differences. I think that comes through clearly.
Like the theme of sacrifice, it’s clear they wanted this to be one of the things it’s about (though I don’t think they really succeeded in making the teamwork feel earned).
I personally don’t see how the sacrifice angle isn’t just as clear. Jyn’s mom sacrifices herself to buy Jyn some time, Galen in a way sacrifices himself to put a weakness in the weapon, Saw sacrifices himself to let the others get away in time, Cassian talks about how his life has been full of sacrifice, Jyn has to make a decision to join that life of sacrifice (rather than ignore the struggle), and of course the whole team and a whole lot of rebels make the ultimate sacrifice in the end in the hope that they can give the others the plans to destroy the Death Star.