The Ethanol content in Diesel fuel I believe has risen considerably since your vehicle was manufactured, perhaps others ca confirm.
It is unrealistic to expect any fuel hose to last 30 years even without the additional Ethanol, granted many will but many wont hence the MTBF measure (mean time between failure) 7 years is not that premature, all cars will have had a few items fail in that time which go on for years on other vehicles, all of them would warrant someone (without an understanding of MTBF) saying "this should not fail at this age/mileage", you read it pretty much every day on this forum.
Thanks for the heads up though, I had not heard of it before, yours might be the first of many, I will give all mine a precautionary squeeze at each oil change.