When I clicked on the Report A Bug button it gave me the Idea form, not the bug form, so I do not have the normal Bug questionnaire to fill out.
I am playing on a Mac. This is a totally unmodded new game I just started to test this issue, which has never used any mods.
I placed a family of previously saved sims, two of whom were already Arch Dukes into a new world. The crown menu in the new world showed the Arch Dukes as nobles in the world. The game was saved in live mode.
I deleted the whole sim family while in the sims manager. The crown menu showed this:
I saved in live mode, and exited the game. I opened the game again and navigated to the world. The crown menu showed this:
Adding the same family back into the world did not delete the llamacorns. It did add the new Arch Dukes, but the llamacorns remained.
I was able to start another new game and repeat this by following the same steps. The game will not allow for the complete deletion of noble sims. Something still persists.
Even more troubling is what happens when you delete the sim who pulled the sword from the stone. Simcalibur is missing from the stone in the square. The sim who owned it is gone. The sword in their inventory is gone. The next sim to visit the stone is given a popup asking "Where is the Sword?" This is the answer:
Trying to reset the stone in debug does not change anything. Exiting the game and restarting shows the sword back in the stone in build buy, but sending a sim to the stone in live mode shows a missing sword. As far as I have been able to troubleshoot, NOTHING will bring the sword back into the game. And trying to add the same sim back into the game from the library does not work. The sim, even if saved with Simcalibur still in his inventory, or mounted on a wall in his house, is not recognized as the sim who pulled the sword from the stone. A mounted Simcalibur in a house is missing after the owner was deleted. So, again, something still persists.