The line is something like this:
“Well, I did not realize Skywalker was so wise. We will give him and the Jedi order the death he desires. [Once the rebels are gone, we will go to the planet and destroy the entire island.]”
I think the last part capitalizes on Rey’s passion for protecting the caretakers as seen in the deleted scene where she tries to do so. With no one on the island in this version, and nothing in Rey’s mind to correspond to anyone else living on the island, Snoke threatening to destroy the whole island seems excessive and blunt.