The news comes via the official Google Search Liaison Twitter account. It tweeted that the change was the result of feedback from users who wanted to see more site variety in their results.
Having many different sites appear on the first page of Google results should be beneficial for users looking for a larger range of sources. It might also bring more exposure to smaller websites, who often appear further down the list and therefore don’t get as much traffic.
This site diversity change means that you usually won't see more than two listings from the same site in our top results. However, we may still show more than two in cases where our systems determine it’s especially relevant to do so for a particular search….— Google SearchLiaison (@searchliaison) June 6, 2019
Google stressed there would be some cases where more than two results from the same site will be shown if it’s especially relevant for a particular search. It added that subdomains and root domains would be treated as part of the same single site, but “subdomains are treated as separate sites for diversity purposes when deemed relevant to do so.”
Google’s Danny Sullivan tweeted that the change—he personally wouldn’t characterize it as an update—started earlier this week and went fully live yesterday.
It started a little bit about two days ago but went fully live today. Personally, I wouldn't think of it like an update, however. It's not really about ranking. Things that ranked highly before still should. We just don't show as many other pages.— Danny Sullivan ([USER=347908]@DannySullivan[/USER]) June 6, 2019
Some Twitter users wrote that they still see multiple results from the same site, but Sullivan said Google continues to work on improving the feature.