You will get a pay cut if you relocate from one office to another today, e.g. moving from New York to Huntsville, Alabama will result in significant decrease in salary.
Correct, but I'm still pretty sure that $BigTechCompany pay is still pretty darn good for the area and the work is probably more interesting too. At the end of the day, $200k in Alabama for an experienced developer is still a fraction of the cost for the same experienced dev onsite in Menlo Park.