True. Some will go other places like you mention and some will remain in their home countries.
In any case, it's not just having talent go to developing countries that I see as a positive, but also seeing other countries' increasing tech scenes. I think having geographical diversification in the tech world is healthy. For starters, if one country ever elects a leader that wants to attack tech and automation as aggressively as the US leadership is attacking immigrants, then human technological progress will be less affected.