Without the holocaust, i don't think it would be seen a morally acceptable, it would be in the same vein as South Africa and Rhodesia.
This moral difference would be the biggest difference influencing behavior. The number of Jewish immigrants over decades may be the same or less or more.
But, the Arab Palestinian case against encroachment or displacement will be far more sympathetically heard by people worldwide, including Jews.
Without the Holocaust there will be support for settling in Palestine and charitable funds available, but nothing like lockstep unity among the world Jewish diaspora in favor Zionism, and certainly not in favor of instances of Zionists doing terrorism or expulsions of non-Jewish populations.
Even within Palestinian Jewish communities there will be more debate, dissent, and effective opposition to attempts to bully out Christians and Muslims at gunpoint.
The Holocaust won't be there as the all-purpose justification for getting them before they get you.
Now, inter-sectarian warfare in Palestine itself can fuel some large-scale evictions and expulsions if it gets large enough. If there's enough instances where Arab Palestinians temporarily get the upper hand and do some massacres of Jews or mass casualty terrorist attacks, then things can escalate and the Zionists could use the occasion to evict populations for security reasons.
Although this is assuming world wars happened, and social views became negative towards settler colonialism.
I think its less about generic attitudes toward settler colonialism and more about whether each side's violence is considered proportional to the provocation. You could end up with Palestine, especially its cities, very crowded with Jewish and Arab populations *both* growing. Outright war is avoided, but the Arabs are feeling swamped. Jews are moving in everywhere, but they're not kicking anyone out of the country. The cost of living is just going up.
Displacement may occur through gentrification (I can live better in Amman) than through panicked flight.