No.That is why I cited Article 49 of the 4th Geneva Convention. An occupying force moving its civilian population into occupied territory or displacing the local population in occupied territory is illegal.
Because Britain was the mandatory power and allowed the Jews to legally immigrate to "Palestine".
It was perfectly legal immigration.
Then Britain left and offered to divide "Palestine" between Jews and Arabs. The Jews accepted. So they were the legal owners because the previous legal owner - Britain - gave the Jews legal status.