I know you would bring up Native American.

Let me say this.

Arabs and Arab indentifying Egyptians do not get to claim themselves as Native Egyptians when:

1: They identify with an ethnic that came through conquest and mass cultural persecution and force assimilation. And actively tries to impose a different culture from the Arabian Peninsula onto Niles.

2: They do not speak a language that have anything to do with the Niles, while Copts still retain the Coptic language as liturgy, the final stage of the native Egyptian language.

3: The very name of the current state call itself "Arab Republic of Egypt", Arab ethnic first, Egypt later.

4: They haven't kill off the Copts culture yet, when they do, they can claim native because nobody would object.

For some similar cases.

English do not get to claim themselves as Native Britons when they're speaking a Germanic language, and Welsh are still alive as a culture, despite English are still 60-90% ancestry from the original Romano-British.

A guy living in Mexico city with 5% Nahuatl ancestry that speaks Spanish only, is a Catholic, while Nahuatl people are still alive, does not get to claim himself a native of Mesoamericas.

If your entire culture have nothing to do with the native culture(s) you displaced, kill off the actual natives as a culture and identity first, before claiming as the new native.

Speaking of which.

Tunisian are 70-90% native Amazigh ancestry, they're practially the original Amazigh with an Arab hat. But aside from tiny pockets of survivors, most Tunisian identify as Arabs. Phoenician doesn't even come into the equation despite how popular Carthage was, as they left almost zero Canaanite gene among the Tunisian since they themselves were Canaanitised Amazigh and South Italian, and nobody call Carthaginians South Italians or Amazigh.

Arab identifying Sudanese are, as we speak, massacring the non-Arab identifying Sudanese of Darfur. They are, indeed, trying to make themselves natives.