This seems like... a really big deal? I know that we're all sort of living in a world where "put ads on your high-traffic site" is a deeply outdated revenue model, but it's still quite a popular one, depending on what corner of the internet you're in.
I think that model is as relevant as ever. Google is just narrowing the list of “high-traffic” sites worth putting your ads on, to exclusively Google properties.
Anecdata, but the rate at which I google something that I basically want to search on Wikipedia but then don't click through to Wikipedia has got to be about 50%. WP doesn't monetize their site, so maybe not the best example?
I guess this could also be indicative of how people use Google (the search engine proper) now. You need some sort of data(phone number, address, trivia fact), and Alphabet has already scraped the relevant site to pipe in that data.