Guide is wrong. I've built 3 rigs in the past 6 months each with an SSD in them and every single one is enabled. Every single time I install Windows 8.1 onto my rig (which has 3 SSDs in it) Superfetch is still enabled. Each install I do on a 9470m or 9480m at work it's enabled. Superfetch has been enabled by default since Vista.
Maybe in theory it's supposed to disable, but in practice it's always been enabled. I don't find it to be particularly a bad thing because it doesn't exactly hamper an SSD at all or cause it harm. People just tell you to disable it to save a bit of RAM.