The thing about the Godwin arguments, is that they are supposed to be about ridiculous comparisons to the Nazis/Hitler. Example, "Oh, so you're a vegetarian. You know who else was a vegetarian?" I would even accept that the comparisons between Musk and Henry Ford and Werner Von Braun were a meant to be jokey and that nobody actually should take them seriously.
But in recent years, he seems to be deadly serious about supporting any European political party on the right, such as AfD, and the Austrian party that ran on a "thy will be done..." slogan, with the "thy kingdom come." actually translating as Reich.
Now he does this at the inauguration? At this point, Musk does not deserve the benefit of the doubt. I have no idea if he just finds it funny, or if he is happy to string along fascists. But this was deliberate, and anyone should be bothered by this unless they are already fascist.