This has never been changed.
The problem is that no one was ever called Palestinians except the Jewish settlers until 1967, when magically all Arabs living in the area, who had always insisted they were Arabs began calling themselves Palestinians. This didn't happen until they got their lunch handed to them in the 1967 war.
The Palestinians are a made up people according to their own leadership.
Indeed Zuheir Mohsen’s admission is lost on the liberals, who have been trying to suppress it for decades. Even worse, pan-Arabism is based on the Nazi notion of pan-Germanism, just as Nasserism and Ba’athism is based on national socialism.