Not to defend musk, but it's not from one specific font. The logo is just Unicode char 1D54F, a blackboard bold X/"MATHEMATICAL DOUBLE-STRUCK CAPITAL X"
A character is nothing without a font though. When you look at a character on-screen, it's being rendered in a specific font. Typing that Unicode character in "Special Alphabets 4" produces the image in question.
The character (𝕏) doesn’t actually doesn’t exist in the font, because supporting arbitrary Unicode characters in every font would be absurd. Paste it into the font preview and it renders a black square.
Of course there are fonts that support every character, the characters themselves would be useless if they couldn’t be rendered by anything. I’m only saying that this specific font doesn’t support the character.