The point here is that sub $40 oil is becoming the new norm. While these countries can weather a 2-3 year drop in oil prices, those short term drops are more and more frequent and the bottom keeps getting lower.
Between electrification of transportation and reduced travel which may last for another 6 months (or much longer, it's not really clear), demand is down. On top of that, any time oil stays over $50/ barrel for a prolonged period of time, shale oil and oil sands production increases putting downward pressure on prices.
Any way you look at it, there is no good news for oil-dependent states.