It is just a suggestion of recommendation. You dont need to, but don't come back whining about a broken valvetrain and say we didn't warn you so. Skunk2 even recommends it, but not required. Even if you don't rev to redline, it is possible to damage your valvetrain.

The Skunk2 Stage 1 cams are slightly more agressive than the Toda Racing Spec A cams, and even Toda Racing recommends at least to upgrade to the Type R valvetrain