Is this the result of institutional racism? I’d say so, but it also can be a cause or underrepresentation in higher skilled employment, even if the employers are not biased in their selection processes.
What he said was "the top x% of the tech population". The tech distribution as a whole is already skewed. If talent was independent of race, you'd expect an equally skewed distribution at whatever talent threshold you set. That's how conditional independence works. His statement is implying that is not true, and that if you set the talent threshold high, you get a different racial distribution. That's a very important distinction, if that is indeed what he's saying.
I really think this is what he's saying, because he's explicitly stating that large companies that recruit nationwide should be have a population equal to the skewed nationwide tech population, because they higher only "the top x% of the tech population". Not confounding geographic reasons (i.e. someone doesn't want to move away from their family), but specifically talent reasons.
For example DC has a huge college educated black population because the government was one of the few places you could get a well paying as a black person with less discrimination. So lots of people decided to settle there. Atlanta has a lot of historically black colleges - creating a pool of educated workers.
In CA, most of the black population came over as blue collar workers in the military, shipyards, and manufacturing. Whereas most of the Asian population is made up of professional worker or affluent educated immigrants.
Yes I am generalizing here. We don't do a good job of carving out the differences for Asian groups. East Asians tend to be super educated, southeast asians tend to not be, and the outcomes are also widely different.