Those examples are not demonstrating oil spots on the sensor. Clarity and dehaze work by creating structure based on minute variations in the raw file. If you take an input, like a small oil spot in an otherwise clear blue field, and apply a massive amount of structure to it then of course it will look terrible. My standard setting for clarity is -10.
100% Clarity and 100% Dehaze aren't allowing you to see the problem. They are creating the problem. What you see in those example are pixels created by camera raw and is not an indication of how much oil is on the sensor.
I'm sure there are instances where oil splatter causes problems. But if you are waiting for a perfect camera to come along you might be waiting a while. Complex systems have complex problems.
I've attached a picture from my aforementioned recent trip. It was taken three weeks after a CMS cleaning. I had not taken that many frames since the CMS. The picture is f6.3 and is un-edited. I think it just shows that it is easy for the sensor to get dirty from oil even after a cleaning.