Earlier quoted context omitted.
That surprised me, too, because in 2013 I was installing from FTP. But mostly from habit. I'm hoping it's because they are going to be using HTTPS with pinned certs to ensure you are downloading from a proper mirror. But that's hope, not actual knowledge.
> HTTPS with pinned certs Is there an FTP equivalent of this?
Frankly, if I was looking to implement this, I'd start with SFTP/SCP. FTP/S is, at best, a rarely implemented kludge.