The March 2020 retrogression of the EB-3 category means that the US government has "overshot" their usage of visas in Fiscal Year 2020 (Oct 2019 - Sept 2020). In order to remedy this, the government retrogresses the visas, which serves as a pause on the issuance of new visas. The Philippine EB-3 date retrogressed because of increasing demand for Worldwide immigrant visas. The Worldwide cut-off date can never be less favorable than any other country’s date.
This happens every few years. Visa approvals will slow or stop starting in March, until the end of the fiscal year in September. In October 2020, new allotment 140,000 visas are released into the system. There is a chance that more visas are released into the system before the end of the Fiscal Year because, from time to time, the government's pause has its intended effect and more visas can be released before year-end.
If you are in any part of the visa process and you do not have your visa issued before March 1, 2020, your case will be held in abeyance at the Embassy or NVC, unless you have a priority date earlier than January 1, 2017 (Worldwide and Philippines).