Am I missing something, or does this article entirely lack any substantiation of the claim made by its title beyond noting that Miami is ranked first in startup activity and Peter Thiel is moving to LA? The only stat about anything actually leaving the Valley is a survey about people intending to move out of the Bay Area that doesn't elaborate on the demographics of the respondents (are they tech workers or non-tech workers trying to escape costs?).

I think the thesis is roughly accurate - tech companies are less dependent on being in SV for success than any time in a reasonably long time, I just don't see much hard evidence backing it up in this particular piece.