Google is testing a new top stories feature and label that tells you that there are new top stories available since the last time you searched for that query. There is a new label that reads "new" and says, "There are new results since your last search."
Here is a screenshot from Gagan Ghotra who shared this with me on X:
It is cool that Google can tell you that there are new stories and results since the last time you conducted that search.
Forum discussion at X.