Correlation doesn't equal causation - the population of surrounding Arab regions / countries grew very fast over the same period of time, as well. But it's true that a part of the Palestinian population growth in the late Ottoman / Mandate period came from immigration from other Arab regions, it wasn't only the Jews moving in. Though rather few of those Jews actually provided jobs to Arabs, so I'm not sure that that immigration was thanks to the Jews.

It's also true that the Palestinian national consciousness was to a large extent shaped in reaction to Zionism, rather than preceding it. Some Arab villages that ended up in Israel after 1948, the Druze and Bedouin ones especially, probably never viewed themselves as Palestinian at all.

But if you start arguing that one people has a more valid claim to land than another just because the first already had a national consciousness driving them while the second doesn't but just happens to be living there, that's pretty much the definition of colonialism. Though more the American colonists' kind of colonialism than that of the Europeans in Africa - not exploiting the locals, but pushing them away.