The issue with oil in the engine getting water is from condensation not that it really absorbs water from the air like brake fluid. There is so much more surface area in an engine filled with air than what is in a bottle. In my case only driving a few thousand miles a year, last year it only drove just over 1,300 miles, the engine sits a lot and doesn't run much giving it a better chance to get condensation than a vehicle that drives 15,000 a year.
First off, reread that post and what I was replying to. It was in regards to another member expressing concern that oil in an opened container(a bottle/jug) would absorb water out of the air.
Second, you say it sits long and doesn't get run much. Time sitting doesn't matter as much as time running. When it runs, how much does it run?
Yes, as the engine cools, moisture that is in the air inside the engine will condense inside the block. That isn't a lot of moisture though. While the engine is stopped you aren't getting much, if any, air fresh moving through there. Once the moisture is condensed and the engine is cool, that's it until the next heat cycle of the engine and fresh air is pulled into the crank case. If you drive it for a meaningful amount each time the oil will reach operating temperature which exceeds the boiling point of water. The moisture in the crank case will burn off (boil or vaporize) and get extracted via the PCV system before the next cycle.
Problem for typical lower mileage engines is that they get run frequently for short periods. They are started and driven for short distances so the engine gets warm enough that it causes condensation when it cools. The engine is never run long enough to fully warm up and burn off the moisture that collected from the previous drive. Because it happens frequently, two or more times a day, the condensation has a chance to build up.