It would be of interest to see the same map labeled as "Arab Settlements 1947"
When the White Paper was issued in 1922, there were 80,000 Jews and 500,000 Arabs in the British Mandate (including Transjordan). BY the 1936 census, the Jewish population had risen to 380,000 (30,000 in 1936 alone). But the Arab population had also risen as dramatically, to 1.25 million, attracted by the economic activity of the Jewish yishuv.
Refugees "found a shelter and a sanctuary there, so that this land, not largely productive of the means of life, became a fountain of charity and hospitality to people in distress. Land reclamation and cultivation and great electrical enterprises progressed. Trade made notable progress, and not only did the Jewish population increase, but the Arab population, dwelling in the areas colonized and enriched by the Jews, also increased in almost equal numbers. The Jews multiplied six-fold and the Arabs developed 500,000, thus showing that both races gained a marked advantage from the Zionist policy which we pursued and which we were developing over this period."
(Churchill, defending the policies under the first White Paper, in debate, House of Commons, Aug 1, 1946)
80% of the land in Israel's 1948 borders was purchased.
Numbers can be argued, but it was only Churchill's government which had collected them. Other narratives are important, but Newt is following this narrative, a narrative which is continued in the nakhba, wherein Arab armies denied the Palestinian Arabs the rights of a separate people in a separate state. Instead, they "invented" a narrative of permanent refugee status, generation after generation, which is legal no where else.