If an island is owned by one person then just immigration to that island is dependent on the will of the owner.

If a group of islands is owned by one person then just immigration to those islands is dependent on the will of the owner.

If a group of islands is owned by a group of people then just immigration to those islands is dependent on the will of the owners.

New Zealand is a group of islands owned by a group of people – Just immigration to New Zealand is dependent on the will of the owners.

Immigration is dependent on ownership.
Freedom is only relevant if it is the owners’ will (or duty).

Let’s see where this goes…