Elon Musk confirmed that Tesla plans to use a different alloy for the Cybertruck. On Twitter he confirmed that SpaceX was changing the alloy on their next spaceship. He was then asked if it was changing on the Cybertruck and he said yes.
When the Cybertruck was revealed Musk said it would be made from Ultra-Hard 30X Cold-Rolled stainless-steel structural skin to Tesla armor glass.