According to the changelog given with the preview, netherite armour and tools have the wrong rarity. As stated in the changelog any crafted item has same rarity as the component with the highest rarity. By this definition netherite armour should have the uncommon/yellow rarity as the netherite upgrade has said rarity. You craft netherite armour and tools with their diamond counterpart, a netherite ingot and the netherite upgrade to create netherite armour and tools.