This is something that Google wants users to be more aware about moving forwards. This means that sometimes when the search results are changing too quickly due to a rapidly-evolving topic, Google will now display a warning and will advise users to wait until more reliable sources can be found.
According to Google, “While Google Search will always be there with the most useful results we can provide, sometimes the reliable information you’re searching for just isn’t online yet. This can be particularly true for breaking news or emerging topics, when the information that’s published first may not be the most reliable.”
They add, “To help with this, we’ve trained our systems to detect when a topic is rapidly evolving and a range of sources hasn’t yet weighed in. We’ll now show a notice indicating that it may be best to check back later when more information from a wider range of sources might be available.” These changes should already be live and is expected to roll out to more users over the coming months.