The author states that pihole sending requests to 8.8.8.8 (Google) is worse than sending requests to your ISP. I disagree. I have always had terrible experiences with Comcost's DNS. I trust them less.
So you're not asking the ISP for abc.google.com, but because they provide the internet, the ISP will see all your requests, including the UDP request to the .com TLD, google.com's DNS, etc