I find it hard to imagine that anyone, let alone Tr*p and his coterie, can just spin up an engaging social media platform in short order, especially if they can’t be hosted on well known cloud infrastructure.

Additionally even if he does somehow succeed, it seems unlikely that this platform would get any kind of traction beyon his most fervent supporters. Twitter, Facebook and YouTube are great because people are on the platform for other reasons. Not so much for a dedicated site.