I think the most jarring aspect of Elon Musk's persona change over the last decade is his dramatic shift in communication style from use of elaborated codes (detailed, precise language) to restricted codes (implied social assumptions).

Middle to upper classes tend to use elaborated codes due to the need to communicate with others that do not have a shared social background, while working classes tend to use restricted codes based on a smaller community's shared social background.

It also explains why middle and upper classes tend to have such a strong reaction to his shift in communication style. People accustomed to elaborated codes might interpret his new style as evasive, misleading, or even incoherent while those who primarily communicate in restricted codes may perceive it as more authentic and engaging.

Elaborated code users (e.g. academics, engineers) expect precision and clarity, while restricted code users (e.g. online cultures) assume shared context and implicit meaning.