What makes information newsworthy?
There are eight categories that make information newsworthy. Timeliness, prominence, proximity, significance, unusualness, human interest, conflict and newness. (Wilcox, D. L. & Reber, B. H. (2016). Public relations writing and media techniques. London, U.K.: Pearson.) Anything that could fall under one of those categories would be considered newsworthy.
Personally, I do think pop culture information should be classified as news. Those topics fall under human interest, conflict and newness. Most of the time, the news is conflict and newness. For human interest there are a lot of people that through social media, feel connected to celebrities. When things happen to those celebrities it becomes human interest for the viewer.
Wilcox, D. L. & Reber, B. H. (2016). Public relations writing and media techniques. London, U.K.: Pearson.