Jews are allowed to live anywhere in the US only if they are US citizens. Jews and Arabs are allowed to live anywhere in Israel only if they are Israeli citizens. Both countries have a right to exclude anyone who is a non-citizen, as does every other country in the world.
So the real question is whether Gaza is rightfully part of Israel, in which case Jews should of course be allowed to live there, or whether it belongs to “Palestine”, in which case the Palestinians of course should have a right to exclude anyone who is not a citizen or their “country”. It seems that Gallant (as well as the Biden administration) holds that Gaza doesn’t belong to Israel. If you disagree with them, you need to explain why the State of Israel should have sovereignty over Gaza (there are of course many arguments to be made both in favor of or against such a position).