We’ve realized that there has been some confusion between deleting an account and deleting a login method. We want to reassure you that deleting your Niantic account in one game will not delete your accounts in other Niantic games.
Recently, some Peridot Keepers have unlinked their login methods from their Peridot accounts, temporarily removing their ability to log into other games like Pokémon GO. The Niantic Support team has helped these Keepers & Trainers recover access to their Pokémon GO accounts, and we’ve added a safeguard that will preserve at least one non game-specific login method (e.g. Google, Facebook or Apple login) for players of multiple Niantic games to prevent additional issues.
If you are having any issues accessing your account, please contact support at https://niantic.helpshift.com/hc/faq/2030-how-to-contact-support/.