All of those sites are simply aggregators for manga scanlations. Which means, they take the work of the various translation groups from their various websites and put them all in one place for you to find. For the most part, they don't 'work' on any of the manga on their site themselves.

Which means, even if the aggregators all get shut down, the various sources who still translate and upload the manga are still there. If you pay attention to the names of the people/groups who translate your manga, you'll be able to find them wherever they end up.