I spent eight years at Google, starting long before these DEI mandates came in (and did over a hundred interviews during that period). I think the person you're responding to is being sensationalist, but I also feel the way these measures were rolled out did end up missing out on a lot of great hires due to them not fitting the perceived makeup of the company.
Funnily enough, I recall a specific meeting where they were planning to roll out measures to equalize pay between male and females. Prior to the rollout, they did an internal audit to understand the extent of the problem, and the audit came back highly favoring females over males. To Google's credit, they didn't move forward with it.
If you were at Google that long, try to find someone who sat in on a hiring committee. They rubber stamped packets of candidates below the bar all the time. Interviewers were kept out of the loop by design. You rarely knew if the people you interviewed were hired or not (unless you worked for a small office). But yes, I agree, Google passed on many good candidates over the years, and thats why they let you interview multiple times. If you interviewed in 2011 and "just missed", you'd likely be a strong hire in 2015.
Perhaps this has changed over the years. I recall there is a website listing all the people you have interviewed and their status (e.g. upcoming interview, rejected, application withdrawn etc)