@Chris Martin
If you read the suspension letter it says specifically "This guidance affects Appendix 1.0 – Mortgage Insurance Premiums of the FHA Single Family Housing Policy Handbook 4000.1, and reinstates the Appendix in affect prior to the issuance of the update communicated in ML 2017-01."
When one goes and looks at appendix 1.0 in the FHA Single Family Housing Policy Handbook, the very first thing it shows is...."Annual Mortgage Insurance Premium (MIP) Applies to all Mortgages except: Streamline Refinance and Simple Refinance Mortgages used to refinance a previous FHA endorsed Mortgage on or before May 31, 2009 Hawaiian Home Lands (Section 247)"
Take that in conjunction with the fact that on the first page of the Handbook,
Section I-A says this "The requirements outlined below in subsections 1 through 9 apply to both Single Family (one-to four-units) and Multifamily Mortgagees." which means that the FHA considers 1-4 Unit multifamily buildings to be under the Single Family umbrella. So I can buy a four family, a multifamily building, use an FHA Loan, and be hurt by the suspension letter you linked.