Have no fears about the problem occurring after only 100 miles. I've been put through a rapid learning curve with the XE, to finally realize how "no longer like a 20th Century car" these new vehicles are, especially the performance ones.
When you get a caution message like that, (mine was for a loose side airbag wiring harness) I think of it as cool that my car can actually self-diagnose and detect an issue that, in the past had to wait until a part had actually broken down somewhere or a gloppy-doodle sound coming from the bonnet.
Want to experience an incredible surprise?
After a day's journey, when you bring the car back to your home, if your garage or driveway is calm and silent,... park the car, turn it off, and just sit patiently in the driver's seat, listening to the cabin... There are half a dozen different modules, relays, "systems", that you hear switching over, turning on/off, powering down, each at its own prescribed time, all AFTER you've turned the ignition off.
It's eerie, but also marvelous. The car is always doing something behind the scenes that is somewhat far away from our mechanic notions of what "a car" ought to be doing.
I would also like to add a bit of advice: When you're on the road, and you witness any sort of warning message or caution light come on, take is as an opportunity to TEST the "Optimized Assistance" switch located in the console over your head. Push that blue button, and speak directly with Jaguar-central. Your VIN and location should be transmitted to their monitor screen, confirm that they know you and give clear advice to you, etc. It's better to assess your link to Jaguar now, than to wait for a real problem or emergency.
This is YOUR Jaguar. Put it through its tests, and enjoy the results.