If you talk to tech folks about poverty every single one of them will give you a great essay like answer about the injustices of the world and how they support the working class, but the very same people will treat the cantine staff when nobody is looking with lack of respect that I've not seen in many other places. And that matters personally because that to me says more than speech.
And I would say that at least from my personal experience this is not just because people in tech earn a lot. Before I worked for a stereotypical tech company my first gig was in finance, and altough bankers tend to have a bad reputation, I've rarely seen someone mind taking a train through a rough neighbourhood, or mingling with people from say a working background.
In tech on the other hand I have to say I know a lot of people who are so insular in how they live their lives while at the same time touting all kinds of inclusivity that it's honestly pretty angering. It's not that I'm surprised that rich people don't think about poverty a lot, or that the OP is surprised that predominantly affluent white coders don't have a personal connection to african-americans getting shot, it's that if they're going to voice support it better be more than just lip service.
The company has made unambiguous statements of support for BLM yeaaars ago (tweeting "we need racial justice now" after talking about Castile and Sterling IIRC), and a company-wide meeting was interrupted by BLM protestors sanctioned by the company taking the stage (after IIRC Trayvon's shooting).
The author's complaint isn't that Google or its employees overall are silent on BLM. It's that their their specific team isn't talking about it with the frequency that they've arbitrarily decided they should. It seems like a pretty typical case of thinking that everybody should prioritize the exact political issues in the exact order and degree that you yourself do. You could make the exact same complaint for "people don't talk about DAPL as much as I'd like", or Nestlé and water rights, or climate change, or Syria etc etc. The only difference is that it's be ludicrous to consider any of the latter complaints as implicit discrimination, and yet for some reason you don't think it's ridiculous in this case.