That's not a good question. There have always been people who wouldn't have wanted to move to the US, for various reasons. People usually like to stay at home, in a culture they're familiar with, near people they know, unless something really pushes them to leave.

A better question is: take a random sample of 100 devs in Ukraine and India in early 2016 and offer them a green card, and then do the same today. How do the numbers compare? Now you're seeing how many people would have liked to come here, and now have changed their minds because of recent political events.