US Arab-American and Muslim leaders have not given any counter proposals. It was a suggestion, and not even one of the 22 Arab Countries will take them in while Gaza is being rebuilt, so where do you want them to sleep, eat, wash, go to school, and keep warm during the many years it will take to re-build Gaza with all brand new building materials– in that rubble? It will take years to clear aways all the rubble.
As you can see, Hamas did not even have a back-up plan after massacring so many Israelis and taking hundreds of hostages of all ages on Oct 7, while violating every known UN Rules of War and Geneva Conventions to set the ground rules.