Dr. Pete, Pete Meyers, from Moz, posted on Twitter "Any algo update that impacts query interpretation or relevance will impact Featured Snippets." This was retweeted by Google's John Mueller, so I guess that is a vote of confidence without passing DA ;-). In all seriousness, we've all seen it, featured snippets are very finicky and change a lot but algorithm updates can cause them as well.
Here is the tweet:
General FYI -- Any algo update that impacts query interpretation or relevance will impact Featured Snippets. Featured Snippets *are* organic rankings, and they're still (best I know) selected from page one. The selection is a separate process, but they're built on the core algo.
— Dr. Pete Meyers (@dr_pete) November 6, 2019
Google has said numerous times that specific algorithm updates directly impact featured snippets, including a freshness algorithm in February and even BERT - because Google understands these longer phrases better. But also, we know that the featured snippets algorithm is heavily using machine learning above and beyond just BERT. And Google has told us these featured snippets update frequently because of it.
That being said, most often, a featured snippet is also found in the top ten results on Google - often top three. But not always.
Interesting - do you have examples? I've only seen it when "page 1" was being resized (like requesting 100 results in the URL), which occasionally pulls a result from 11+. It's been my understanding that these are real-time, but then you see weird exceptions that make you wonder.
— Dr. Pete Meyers (@dr_pete) November 6, 2019
I have seen random examples over the years, have you?
Forum discussion at Twitter.