[MLL67RSSS]

All the systems are closed. The crankcase is closed and not vented. The only way moisture and/or condensation that occurs while the engine warms up to escape is to cycle through the PCV system to get burned in the cylinders. This happen while driving the car normally as the PCV system functions. The car just being started and sitting idling can accumulate more and more moisture in the crankcase and eventually the oil every time it is run and not driven normally. Also if the exhaust system does not get hot enough to burn off all the moisture that accumulates in the system it will just sit in the exhaust system and rust it out.
One more, the byproducts of combustion that turn the oil dark are acidic. The older and darker the oil is the more acidic it is. Best to get fresh oil in there while it is just sitting all that time, don't need it etching into the parts that are submerged in it.
But you can believe whatever you like and do whatever you prefer.