I know that the two situations are not identical, but this is reminding me of the Axis’s massacres of hundreds of thousands of Roma, Sinti, and Yenish people. They were not quite subjected to the same extermination programme as European Jews, and these minorities suffered fewer deaths, but their tragic fates were frequently intertwined with Jews’ anyway. There was a similar lot for Assyrians when the Central Powers focussed on exterminating Armenians.
Not being Palestinian myself, I hesitate to argue that the Lebanese and the Syrians are also victims of the Nakba, but I can see some future historians arguing as much. This is clearly another case of one extermination campaign affecting other humans in addition to the main victims.