The ship has sailed. If the job is outsourceable, they'll adjust regardless. There's not much inherent value in being from the same region as the headquarters & most of what there is comes from timezones.

Much like the threat that food workers will be replaced with robots if minimum wage increases, this is a threat without much bite. If companies thought they could get equal workers by outsourcing and reducing salaries, they already would have. Either being in office is a competitive advantage, or it isn't. We'll find out in the coming years, but I'm pretty sure the answer will be "it depends". And most people will readily accept a pay cut for lower salary if they can live in a lower cost of living area.