I think this is Elon trolling and pushing the boundaries of what can be done. It‘s being edgy and provocative, while obfuscating his true intentions.

Elon used a fascist salute twice in public on stage to thunderous applause. Now he gets the support of the actual fascist right. However all he mainstream republicans in the audience who cheered now have to defend him as well. This will have no consequences for Elon. It was pure demonstration of his power to do whatever he pleases, both to his side and to the opposition. This also gives Elon attention and amuses him.

Elon might call this salute the heart (of America) salute and repeat it in the future. Any other rightwinger who loves trolling the libs now has a role model. Salute from the heart, such a harmless gesture, and it gets the normies all upset. Do it as a laugh first and then for real over time.