That's the part that rings false to me as well. So much anti bitcoin and generalised anti-cryptocurrency stuff from Trump over the last couple of days... but he is starting a crypto thing in secret?

Incidentally, decentralised social media has been done and is solved as a problem - enter the fediverse. Which is a pretty sound initial iteration of a technology piece, for which there will undoubtedly be successive generations as flaws are addressed, just as is the case with any new comms or software paradigm.