In most cases, the debtor, dependent upon a line of credit from its secured lender, and having a close professional (often even personal) relationship with a specific loan officer, will be sure to notify the lender of its change of name (and any other changes of importance). Even without such notice, the lender is likely to discover the name change soon from documents concerning the debtor that routinely cross the loan officer's desk. These documents may include quarterly financial reports that the security agreement requires the debtor to supply the lender.
Article 9 deals with the unexpected, however. Thus, assume the rare case in which the lender does not learn of the name change for a significant period of time.