I think the tax bill from last year helped some with this[0]. Apple announced that they would be bringing back billions of $ from overseas holdings due to changes in the laws, and investing it in the US.
Google has been expanding in NYC for a while. Back in February, they bought their existing building for $2 billion[1].
Mitch McConnell stated that the tax cuts increased employment. Politifact rates that statement as Half True[0]. In reality, it's fair to say tax cuts created an environment that was conducive to hiring, but also, the levels of hiring have been pretty steady since 2010.
That being said, there's even less evidence that this is even Half True in the tech industry.
Google, Apple, Amazon had been hiring like crazy well before Trump came into office. Google and Amazon revenues have gone through the roof in the last decade and they have doubled quadrupled their workforce. This is largely a PR move to respond to Amazon's show. And Amazon itself got started to extract maximum tax incentives from cities. Their HQ2 RFP was announced before the tax bill was passed
Google has been expanding in NYC for a while. Back in February, they bought their existing building for $2 billion[1].
[0] https://www.nytimes.com/2018/01/17/technology/apple-tax-bill...
[1] https://nypost.com/2018/02/06/google-to-buy-chelsea-market-b...