If it had been Aang who took that lightning strike for Katara in the exact same way Zuko did (same framing, same music, same slow motion desperation, etc.), people would be calling it the most romantic moment in the series. Nobody would be arguing it was just something the Avatar would naturally do for anybody. But because it's Zuko and Katara, suddenly there's this push to strip the scene of all subtext and act like taking a potentially killing blow for someone in one of the climactic emotional scenes of the show doesn't mean anything
Nobody is saying that Zuko taking lightning for Katara is Irrefutable Proof that he was canonically in love with her. That's not the point. The point is that the scene is charged with emotional intimacy and is framed in a way that audiences have learned to associate with romance. You don't have to ship zutara to recognize this, nor does the ship not being canon change that fact. And the thing is, Bryke knows this. They know that the scene is romantic. Why else would they get rid of Zuko's scar?























