As someone that has been through a lot of life changes with two small children - I can honestly say that these kinds of changes might be uncomfortable but as parents if we lead the discussions in an optimistic way, the kids will be fine. Kids are so resilient, they will have friends in whatever classroom or school they find themselves in. They can play with old friends on weekends or afternoons, and meet new ones too. It really will be OK.
Every time we are in one of the schools my husband and I talk about how incredibly nice the schools are and the amenities and programs that are in place that we didn't have. We are all so blessed to have what we have.
And diversity is GOOD. When they grow up they will live, work and worship with people of all incomes, faiths, skin-colors etc. Better start now!