Hey there. Bungie does not offer a way to 'delete' your Bungie Account; players in the EU or the state of California can use the privacy request form to request an account anonymisation. However as you're terminating your agreement with Bungie that enables them to handle your personally identifiable info, an irrevocable game ban is applied to all of the linked game accounts. So this is not a way to work around the account unlinking policy change.