I think to understand the culture we’re increasingly living in people need to learn more about the history of Gamergate, pizza gate, 4Chan and the whole approach to trolling and culture wars which has been playing out over the last few years, and which Musk seems to be absolutely steeped in (as his “pedo” comments about the British cave diving expert demonstrated).
Acknowledging that Musk deliberately threw that salute in those circumstances (fully knowing knowing what it would look like) doesn’t mean you have to believe that he is a dyed-in-the-wool Nazi who is finally revealing his true colours.
More likely I think is that he saw it as something more like a dangerous prank, an adrenaline rush, something he could deny but which would be recognised and supported by the audience he now wants to be part of. He knew it would generate a strong reaction, and he knew that it would trigger another round of culture war arguing. He’ll also know that he is currently very well protected by Trump, he is the richest man in the world, and in his own mind he is essentially untouchable.
I think he did it so that when he got off the stage he would get a load of locker room style slaps on the back from his new friends saying “Man, I can’t believe you did that up there, that was SO COOL BRO, the Libtards are going to go MENTAL” and he gets to be the cool rebel and get the bad boy approval he desperately and quite pathetically craves.
Then he can sit back and chuckle at all the comments that are generated, and feel that he is at the centre of the global conversation. Once the fuss dies down he will do something like it again.
These are the times we live in - an Oligarchy in control of the US, a world at the mercy of billionaire trolls, no accountability, no morality, just chaos and profit.