Meanwhile, the way that plays out is that Google hires all the talent by fairly paying more than the startup can, then can turn around and say "your company is a dead man walking, you can either sell us your tech, or crash and burn with nothing", and the only fiscally responsible decision is to sell.
Antitrust is also federal and is probably generally supreme over state law. E.g. even if Google fairly acquires talent according to state law, it can still be determined to violate antitrust.
This poaching scenario (where Big Co pays above market to a large number of employees to drive a competitor out of business) is very similar to dumping (selling goods below market etc.), which has been illegal for a long time even though "selling goods" is generally legal.
However, since the government (DoJ, FTC, etc.) is the ideal litigant, you actually need someone who works there to not get fired for long enough to complete investigation and enforcement. In a lot of anti-trust cases, all the direct participants benefit: the employees get paid more, Big Co consolidates power, and Small Co gets paid off. The "losers" are most distant like their customers or uninvolved competitors who aren't in a good position to sue.
does anyone know if the employees who didnt get poached got their equity paid out?
That the new "investor" choses to let their investment die may not matter, it would also be cheaper to selectively buy out investors than buy out all equity in the company.