If I suspend all possible disbelief, the best scenario is a rich white kid raised in Apartheid South Africa giving "Roman Salutes" to troll people for his own personal LOLs?
I tried, watching the video a few times. I can't believe that he didn't know what he was doing.
At best, he wants to demonstrate that he can make one of the worst gestures anyone can do in this position and suffer no consequences. Some kind of demonstration of power.
"... commonly considered a symbol of fascism that had been based on a custom popularly attributed to ancient Rome.[1] However, no Roman text gives this description, and the Roman works of art that display salutational gestures bear little resemblance to the modern so-called "Roman" salute."
Source: https://www.bloomberg.com/billionaires/profiles/elon-r-musk/
And he isn't leverage. In the end, he sold Tesla share and bought Twitter with cash, contrary to what most newspaper wrote (and never corrected).
While (ancient) Romans may have not done this salute, the salute is commonly referred to as Roman salute nonetheless