Happens pretty often - by accident, that is. My luggage went on a trip all of its own (someone loaded it into a plane bound elsewhere than I was going), so I was peppered by e-mails where it's now for the next few days, while it was misrouted to all sorts of weird places "oops, lost it again! no wait, there it is! no wait, lost it again!". Got it back at last, no damage.
Why not? It's been through the same security as everything else, including all the air freight that's also on board that nobody seems to think about. Usually they'll offload it as a convenience for the passenger but not always if time doesn't allow.
Sometimes this happens even without a strike. Once I flew San Francisco - Houston - Little Rock with about a four-hour layover in Houston. When I got to Little Rock my bag wasn't on the baggage carousel - it turned out they'd put my bag on an earlier flight. (I wasn't on that earlier flight because the long connection turned out to be a lot cheaper than a short one.)
That doesn't make sense, how would they ever get misdirected bags to you if bags weren't ever allowed to fly without their owners being onboard?
It happens all the time that bags get to a flight that the passenger misses and passengers get to a flight that bags miss. Not remotely unusual. It's happened to me recently too.
I guess it’s different if the airline does it rather than if a passenger potentially engineers a situation that their bags fly but they are safely on the ground