Sit back and think about the crankcase environment. It's complex.
Water is a significant byproduct of combustion, but the vast majority of it goes out the exhaust pipe. The small amount of water introduced to the crankcase enters via blow-by, i.e. leakage past the piston rings. Leakage on the compression stroke introduces atmospheric water only, in vapor phase. Leakage on the power stroke is a hot gas. As a hot gas, the combustion byproduct water is also in vapor phase. If it remains vapor, it's going out the breather with all the other gasses.
The water vapor only changes to liquid phase when cooled. The only periods of operation capable of cooling the hot gas are just after cold start and later, after shutdown. When we discuss removing water from oil, that is the water we're talking about, not water produced when everything is at full operating temperature.
Returning to hot operation, the manufacturer's stated minimum oil temperature, in the context of water, is probably based on saturation. The quantity of water vapor supplied via blow-by is some small percentage of combustion water. The percentage would vary with leakage rate, worn engines passing more into the case and tight rings sending more of it out the exhaust pipe.
Although variable, for any given quantity of fuel burned there will be a quantity of water introduced to the case. Hot air will hold far more water than cold air. At saturation (i.e. 100% RH), air at 140F will only hold about 130 g/m^3, while 160F will hold 206 grams and 200F will hold 470 grams. Because piston ring leakage is variable across the fleet, we can't know an exact figure for the quantity of water we must maintain as vapor, but I'll bet it's less than 130 g/m^3 with good tight ring sealing. Leaky rings might require some higher temperature to keep a greater quantity in vapor phase. On the other hand, an increase in the quantity of water might not drive the temperature requirement up proportionally because more leakage would also increase breather flow, thus the grams per cubic meter might not change very much.
A few years ago I beat my wee brain pretty hard to establish a dew point for breather outflow based on combustion chemistry, and came up with 125 to 145 F. It seems to align pretty well with Lycoming's minimum oil temp recommendation.