Here we have it! Finally! The answer to how the Skywalker lightsaber came back into galactic events. This is from the new Star Wars: Launch Bay at Disneyland:
Anakin Skywalker constructed this weapon at the start of the Clone Wars, and it was later passed to his son, Luke. Luke lost it in battle on Cloud City, but someone salvaged it from the city’s industrial depths.
And that is now it got back into circulation! We kind of guessed as much, but who that “someone” is and why is the interesting story. Was it on purpose?