I remember that question and the response.
I recall answering that accounts obtained via a purchase of assets (including from a non-covered institution) are not considered accounts or new accounts under both the CIP and Beneficial Ownership rules.
Brian then added (and these are his words from a confirming email today): "The beneficial ownership rule uses the same definition of 'account' as the USA PATRIOT Act. The CIP section of the BSA Examination Procedures cites that an account does not include, 'Any account that the bank acquires. This may include single or multiple accounts as a result of a purchase of assets, acquisition, merger, or assumption of liabilities.'
"What was discussed during Top Gun was a response that FinCEN provided via a question to the helpline which notes that even for acquired assets, if one of the loans renews and is not covered by the exceptive relief from September 2018, the Bank would still be required to treat the renewal of an acquired account as a new account and obtain a beneficial ownership certification at the time the account renews."