A famous counterpoint to your statement that eighties film stocks would not be able to capture that kind of low-light high-contrast scene: Barry Lyndon (released in 1975).
However, it's pretty much guaranteed that both the old and new scenes mentioned in TFA have a _ton_ of extra lights and flags just out of camera. If anything, the article is pretty naive in assuming that they just walked up to some diner and started filming using available daylight.