Someone could have dinged your screen, accidents do happen; and then while you were away, maybe the interior got hot and the screen failed. It's unfortunate, but your insurance should cover it.
It's like the glass that gets dropped and doesn't break. You put it in the dishwasher, and crack!
Have to admit, it is curious. As for mine, we had just gotten done washing her (the car) top-to-bottom; the point being, I would have absolutely noticed the puncture-type hit (crack). Anyway, shortly afterwards (no more than 15-20 minutes, we were off to pick up a gift bag (at Target) to a function we were to attend. When we came out of the store, about 10-minuts later, my wife caught it and we just stared at it, around the car, at anyone, and everyone even remotely in the area. There were no trees for anything to drop down from, and the space parked in was all of 6 spaces from the front door! I immediately checked the Sentry for any notifications, along with camera activation(s)... nothing. Ultimately, I ended up with a request to get a replacement done by Safelite, but was advised that it would take at least six weeks for them to order (and receive) it from Tesla, in CA. So I opted for Tesla to do it, and like you... my warranty just ran out a month ago; so it was coming out of pocket (or at least the insurance deductible was)! So, two weeks later, at my prescribed time, at my (closest) dealership in Tampa, it took an exceedingly long time to get seen, THEN... WHEN I finally got a Rep in front of me, he explained they wouldn't have it ready until Friday -THREE DAYS from the dropoff date!?!? When I asked why so long, he simply claimed that was the way they do it there. I asked that if I reschedule for a later date (the first one being three more weeks away) could I expect to have a quicker turn-around, but "nope" was the return volley. So, I rescheduled, but have plans for someone else (other than Tesla) to perform the work. For a first time customer of having to take my Model-3 in for service at a Tesla dealership, I was WHOLLY disappointed! (sorry for the diatribe, but thx for allowing the vent)