Musk has outright agreed with tweets claiming, openly and without any dogwhistles, that Jews want to exterminate the white race. He's been mask off for a while if people wanted to see it, and collaborators still make up excuses for him siegheiling in public. They will continue doing so when he shows up in public with a swastika armband or hangs a portrait of Hitler in his office.
The salute can, ofc, still alarm people who didn't pay close attention before, but i wouldn't overrate the propagandistic usefulness. It's been decided for a while who's on which side of history in this.