Earlier quoted context omitted.
And that's not a permanent loss. It may screw up your trip to a greater or lesser degree but I try to build in buffers at least for a shorter delay when I can. I have also had a few multi-day delays--on of which just caught my guided hiking trip with like an hour to spare. And I had already bought a new duffle bag worth of stuff as best I could.
I know it's not permanent. I'm just agreeing with OP that this is misleading.
"Lost baggage is when a passenger’s baggage is lost or goes missing due to an error on the part of the [Kansai] airport."
Perhaps in your case they considered the delay to have been due to somebody else's fault?