I haven't heard of that term before now, but I would argue that XSSI is a way of doing CSRF rather than CSRF, or something entirely different itself. (From Wikipedia: "Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user's browser.")
Apologies if the title made it seem like not using javascript arrays was a magic bullet to preventing all CSRF.