That is dreadful advice. Here’s what @brian, Roon’s CTO, had to say about the matter. A follow up, about running Roon ON NAS devices, is right here.
Unless you’re already running a fanless setup, you don’t need an SSD for music storage. If you do run a fanless setup, and you find a spinner to be audible, try insulating it first, and if that fails, then get an SSD.