Or he could have just renamed the company to "X" and left the current Twitter product as "Twitter." All his hypothetical fancy new stuff could get its own brand

Or he could have just renamed the company to "X" and left the current Twitter product as "Twitter." All his hypothetical fancy new stuff could get its own branding (or not) but he still gets the X. The "Twitter" branding could be subservient to the company branding. Like Alphabet, or Meta, or Microsoft, or countless others... It really seems he just wants to start fresh and kill the Twitter brand immediately regardless of the short term cost. It's a strange play indeed, and it's hard to guess why he wants to disassociate with the brand so strongly.