loan officer originated an application for borrowers. The borrowers wanted to purchase a new home (no address) with one mortgage including new home and current residence. Is this a legitimate preapproval?

Can't answer that with the limited infomation. Did you fully underwrite the loan and issue a committment letter that follows the outline of 203.2(b)(2)? You may also want to review the HMDA Q&A .

In order to meet the HMDA pre-approval test, you have to have a program as well as a credit decision. It doesn't sound like your lender went that far but, as Dan says, the facts are sketchy.