Where they say that? This is the only part I can find about DNS geolocation:
> 2. DNS: Run trick DNS servers that return specific server addresses based on IP geolocation. Downside: the Internet is moving away from geolocatable DNS source addresses. Upside: you can deploy it anywhere without help.
> You're probably going to use a little of (1) [Anycast] and a little of (2). DNS load balancing is pretty simple. You don't really even have to build it yourself; you can host DNS on companies like DNSimple, and then define rules for returning addresses. Off you go!
Seems they are saying that "the internet in general" is moving way from location-based DNS, but that's a bit like saying that the internet in general is moving away from Wordpress.
2. Sending user data (IP address, location) to authoritative nameservers is out of vogue.
There are efforts to send privacy-friendly geo info to authoritative nameservers. But they aren't getting much traction. Which means location based DNS is getting less useful by the day (because it's not working for as many people).
