Eh, this isn't accurate. Both Redshift and Aurora/RDS are used heavily by a lot of teams internally. If you're talking specifically about the primary data store for live applications, NoSQL was definitely recommended/pushed much harder than SQL, but it by no means required CEO approval to not use DDB
Edit: It's possible you're limiting your statement specifically to AWS teams, which would make it more accurate, but I read the use of "Amazon" in the quote you were replying to as including things like retail as well, etc.
While I can understand the cynicism, the real answer is a lot closer to something much more boring, which is most people just don't care about the actual numbers, and if they were to release them, while interesting to a small few, generally no one would actually care.
There's also a common misnomer that Amazon.com is somehow just this one giant app running on a set of servers, which isn't remotely how it's actually deployed, and that's before we spend time arguing whether a team's instances even count as "primary e-commerce front-end stack" or not. :P
Amazon doesn't really have a "primary e-commerce front-end stack" in any concrete sense. They have hundreds/thousands of teams that deploy bits and pieces to a massive pipeline that ultimately makes up what you see on Amazon.com, but each team can have their own infrastructure backing things. Some teams might run everything off a dozen low-end EC2 instances while another sibling team has 3k+ instances; it's really all over the place, and that's ignoring specific events like Black Friday or Prime Day, etc. where teams need to prescale things in advance.
The purpose of language is to communicate, and audiodude did that quite effectively given the fact I chuckled when I read their comment, because I knew exactly what they meant. A "rolling sprint" might be an oxymoron, but it certainly isn't conceptually void. It quite literally does have meaning considering I and many others clearly understood the point he was making through his personal anecdote.
Edit: It's possible you're limiting your statement specifically to AWS teams, which would make it more accurate, but I read the use of "Amazon" in the quote you were replying to as including things like retail as well, etc.