I emailed the FBU last week and recently received the reply below. The reply is slightly different than what I remember reading on the Manila Embassy' website Q&A section:
Thank you for contacting the Social Security Administration's Federal Benefits Unit at the U.S. Embassy in Manila.
The Annual Report Form SSA-7162 is sent from Wilkes-Barre, PA and must be completed by all beneficiaries according to the schedule below. If a beneficiary has a representative payee, Form SSA-7161 will be sent to the representative payee for completion.
Beneficiaries with addresses in Australia, Hong Kong, Japan, New Zealand, and APO/FPO/DPO receive the form every two years. Beneficiaries in countries not mentioned above receive the form every year.
The form is mailed to beneficiaries in May/June and a follow-up letter is mailed in September/October. If the completed form is not received by the end of the year, benefits are suspended beginning with the February payment of the following year.
To avoid the suspension of your benefits, please complete the form as soon as you receive it and send it back via regular postal mail using the enclosed business reply envelope. You do not have to send the form via courier service; however, if you wish to do so, you may use the following address for courier service:
Social Security Administration
Wilkes-Barre Direct Operations Center (WBDOC)
Attention: FEQ Analyst – Courier Service
1150 E. Mountain Dr. Room 341
Wilkes Barre, PA 18702XXX7997
U.S.A.
Do not submit the completed form to the Federal Benefits Unit in Manila or to a U.S. Embassy/Consulate.