The events of Secret Invasion take place in mid-2025, after the events of Ant-Man and the Wasp: Quantumania (2023) in the MCU timeline.
This episode takes place on November 4th: Unity Day, which commemorates November 4, 1612, the date of the popular uprising that expelled Polish Lithuanian occupation forces from Moscow by a militia from Nizhny Novgorod.
When meeting Nick Fury, Sonya Falsworth jokes that she was expecting Paul Robeson. Robeson was a noted leftist and was infamous for his communist sympathies, often visiting Moscow in WWII and during the Cold War.
"Vossoyedinenye" Square is named after the Russian word for "reunification" or "reunion".
The song that Nick Fury plays in Sonja Falsworth's office is "Equinox" by John Coltrane. Equinox is Latin for "Equal Night" and is one of two days every year where the daytime and nighttime are equal.