Planning ahead and being prepared does precede acts by a vengeful person. If you have no skin in the game getting ready ahead of time might seem silly.

Mass deportations are expensive. Deporting Jews from Germany would have been cost-prohibitive. Using Jewish slave labor was actually profitable. It was cheaper to kill them all.

Mass deportation will be quite a boondoggle with money for all involved except immigrants. The family separation will be the biggest tragedy in modern US history in my book. What happens to the children born here by immigrants?