Change of supplier would require an engineering approval, which should normally include both technical examination and extended testing ( where appropriate ). A new loom should have been tested for exposure to heat, fluid contamination and ageing ( accelerated methods used ). If that was done, maybe they considered 10 years was long enough or there was pressure to accept more ecological materials at the expennse of established norms.
This would normally cost tens of thousands and be incorporated in the cost/benefit analysis.
Addressing the original point, plenty of sensors fail with age, but this one risks destroying the engine. Is there any kind of fail-safe system ?
Well, you'd
think so, wouldn't you?! Yet it does happen. Ours is only a small company, and it's usually "money people" further up the tree who overrule things, but as we've all seen, even huge companies like VW have the odd "rogue engineer" (it seems

) who does naughty things despite all the processes and safeguards put in place...
And yes, the original point - that strikes me as barmy too. I had a Citroen BX with an "electronic dipstick" in the 1990s, but it worked without the engine running
and there was a good old-fashioned "real" dipstick as well.
I guess the sensors would be designed to "self-diagnose", up to a point, so for example, if you went to start the engine and the management system saw a short circuit or an open circuit from the electronic oil level sensor, it would probably not allow the engine to start, and report a fault. Maybe they're even sophisticated enough to know that they would expect to see a resistance (or voltage or whatever) between two values and if the reading was significantly outside of those values, it would also flag a fault. Plus, of course, I'd expect there to be a degree of redundancy from the oil pressure switch, whereby if it didn't see oil pressure after a few seconds following startup, I'd expect even more warnings and possibly even engine shut-down. So I guess there's
some degree of fail-safe?
But I'm puzzled that a dipstick isn't an expensive item. What... £10 a car, Maybe? Against that, the electronic sensor would have a cost associated with it - plus the wiring to and from it, and the connectors. It's hard to see how this would save a manufacturer much money.