Does Instagram delete inactive accounts?
Niantic states in their TOS that if an account is inactive for 1 or 2 years they reserve the right to delete the account information. Please keep in mind that all verified deletion requests are irreversible. All game data associated with your account will be completely and permanently deleted. To permanently delete your Pokémon GO account, please submit a request through our web-based Help Center and select “Delete My Account” from the dropdown menu.