First service should have a oil and oil filter change, and as its new oil, it should be at 100% ie, 100% of engine protection by the new oil. Percentage goes down with engine use as contaminates in the oil build up. 15% or less is the time oil should definitely be changed. Likely been an administrative error on data to the ford pass app, by not being updated for your car after the service.
Or, I do not think they missed it out, but.... you may never got the oil and filter change, just check the oil is relatively clean to prove it was done. I always put a sneaky scored mark with a screwdriver on my oil filter to know it has been changed (I never trust mechanics, saying work has been done, and it may have not been done >).
Deterioration/dilution of oil has relatively been a new thing to worry about since EU6 diesel engines came in, where there is more burn cycles of the DPF filter than EU5 diesels, and causes contaminates in the oil. Many car owners like myself have packed in diesel engines and moved back to petrol engines, as there is less complexity compared to EU6 diesels. Petrol engines do not have such a dilution of oil problem.
Some cars are having big problems, like the Range Rover Evoque where the EU6 diesel engine requires new oil and filter every 6 months, or dash warnings of dilution of oil appear. The owners on their websites are angry at such a bad design of emission control causing such fast deterioration of oil.
As my service due warning has come up ( I am fortunate that I have a service booked) I am interested in the post by jimbocanary. Colin puts it all very succinctly but as I have a service warning and not a oil monitoring warning I decided to do a good old Google.
I merely put in Fords Intelligent Oil Life Monitor and there are several items about it. If I have it right, the 39% is either what your dealer thinks is applicable to your annual mileage OR hasn't reset the monitor.
However, if you have a few minutes it is worth looking up the above and it might put your mind at rest.
I appreciate it is a long time ago but my mechanicing days remind me of cars/trucks coming in with a filter full of black 'butter' and oil like treacle. Mainly farmers wagons.
Surprisingly their engines survived for years being treated like this BUT tolerances in machining were nothing like the accuracy of modern manufacturing and modern engines and oils will NOT tolerate abuse however slight. In days of your a' piece of grit' could go through the engine sometimes with little effect but a micron of dirt today wouold be too much.
I rebuilt a Daimler Conquest engine after the driver had literally boiled the engine, after a core plug failed you could hear it coming BUT it was still running. Now no way!