I don't see how this is not already happening pre-WFH: most big tech companies have offices in Ukraine, Belarus, India, China, etc with "low cost" tech workers.
But with WFH, it is an even playing field. As long as everyone is in a similar timezone and logging in from their home and collaborating via Zoom or Slack, productivity differential vanishes. Why do you think you are seeing a sudden flood of biggish companies going fully remote now?
Push for WFH at your peril.
Tech salaries still went up.