Thank you for posting this. I'm honestly a bit surprised that this genre of Google truth-telling is not more widespread, or perhaps I just haven't seen it. Your experience of "the wall" between Latin America and the US is obviously also more poignant than ever. Seeing it described this way, in this context, kinda hit me over the head and is finally making me wonder if the US immigration/deportation mess will ultimately come to be seen as something equivalent to the Iron Curtain. Putting your experiences out there is worth it for that alone, at the very least.
It's not that there haven't been people out there who were willing to yank the curtain on Google, either; I just feel like it's been more of a word-of-mouth thing in my experience. For instance, I knew a guy who was there during the Gmail launch. He made clear to me that "don't be evil" was a slogan created by a later hire, and really had very little to do with the thinking of Page/Brin or later Schmidt, except that they found it to be convenient office propaganda. Thus, he ended up not really believing it at all by the time he was done.
Another good friend of mine was also a contractor in a technical department in Mountain View for a number of years. The US contractor experience (at least in that role) didn't seem as firewalled off as you're describing for the Brazilian contractors, but he was still under the twin guns of "your job is meant to be fully automated eventually, and your primary purpose is training the system towards that" and yearly contract renewals. And of course, it's also where he and his eventual wife got infected with the Bitcoin prosperity gospel, a train they're still riding to this day...
I think the common ground is a fear of loss of authority to which they feel entitled. They learned the "old" ways of SysV RC, X11, etc. etc. and that is their domain of expertise, in which they fear being surpassed or obsoleted. From there, it's easy to combine that fear with the fears stoked by adjacent white/male supremacist identity politics and queerphobia, plus the resentment already present from stupid baby slapfights like vi vs emacs or systemd vs everything else, and generate a new asshole identity in which they feel temporarily secure. Fear of loss of status drives all of this.