Sure, but in terms of angles, a Nazi salute should also point straight ahead from the body rather than to the side as Musk did, nor as I recall (mostly from WW2 movies) is it launched from the left side of the chest in a wide-sweeping lateral movement.
Let's face it, that was not a Nazi salute.
It is not identical to the salutes used by '30s and '40s German Nazi supporters.
It is, however, obviously supposed to be evocative. There is nothing else it could realistically be.
Neo-nazi scumbags use variants and stand-ins to fly under the radar. Just as they do with numerical stand-ins like 14 and 88. Contextually we know what the neo-Nazi scumbags mean.
I have very little doubt Musk, a vocal supporter of fascist and quasi-fascist or white-supremacist figures in the UK and Germany, was sending a neo-Nazi dogwhistle. He probably associates the neo-Nazi shit with fringe online alt-right communities he's familiar with, in the vein of 8-Chan.
I also have very little doubt that although half the modern Republican Party is anachronistically ignorant, the other half is welcoming neo-Nazi dogwhistle politics with open arms (and this latter group includes Trump).