When removing a single account from a Plaid connection where all accounts have terminal statuses (inactive, deactivated, deleted, closed, or revoked), the other accounts get soft-deleted (the account is deleted, but not the transactions or balance history). The other accounts under the same connection are removed, leaving their transactions and balance history orphaned with “Missing account.”

This was reported to occur via the "keep data" path as well (with an account that had all accounts as "revoked").