There are some interesting comments in that thread.
In particular, H1Bs don’t save Google money. SWEs in the same location at the same level are paid roughly the same, regardless of immigration status. (Pay data at Google is fairly transparent). Plus the H1B sponsorship process is expensive for the company. So US citizens/green card holders are probably cheaper for the company overall.
What Google is doing to save money is expanding their engineering presence in India, where SWEs are paid much less.
After being laid off from Google in January I know my org laid off the entire India team as well because they were switching to a cheaper outsource group.
It has gone poorly, no surprise. All the remaining devs bitch about how the new team is hard to work with.
No way!!!