According to Osho, the Upanishads are neither commentaries on nor extensions of the Vedas; they are a radical break—a rebellion ending the Vedic phase (vedanta as ‘the end’) and inaugurating a new vision. They shift religion from priestly, worldly petitions (lower knowledge) to direct, experiential awakening (higher knowledge) through meditative stillness and clarity. Thus, Upanishadic insight stands independent of Vedic ritualism and its fear-and-greed economy.
They aren’t add-ons to the Vedas; they end that old path and begin a new one based on your own inner seeing, not priests and rituals.