I know for a fact that multinational companies are expanding in exactly those areas (plus India) for exactly the reason that it's become very difficult to hire and move people to the US.
Those workers aren't paying taxes in the United States, and obviously the companies hiring people outside of the US aren't going to hire people for those positions in the United States.
I wouldn't mind a new policy that would raise the median "quality" of the H-1B visa holder, even if that meant the total number is lower. Sure, Canada and Western Europe can take the mediocre people we'd no longer be granting visas to, but so what.
But this $100k policy is not going to increase the median quality of candidates. I actually don't think it's going to have a huge affect on things; it's just a token effort to "do something" that Trump's base will eat up, and he'll declare it a success even if there's no improvement or it makes things worse.