It seems like they're rolling all their platforms (Instagram, Messenger, WhatsApp, FB Main) into that one metric? HN's position has generally been that FB Main is on the decline and I'm not sure this metric is enough to contradict that.
Those numbers are for FB Main. The number of active users across all platforms is 3 Billion.
From the linked report: "Family monthly active people (MAP) – MAP was 2.99 billion as of March 31, 2020, an increase of 11% year-over-year."
Globally it's still going strong.