Google updated the video structured data to say that the description property is no longer required. Instead, Google moved the description property item to the "recommended" section, from the "required" section of the help document.
This means that videos that were missing the description property within your structured data are now valid. Google Search Console will no longer report those as invalid, and you may see more valid items showing up in the rich results report.
Also, it means that you may see more of your videos showing up with rich results - i.e., video thumbnails, etc, in the Google search results.
Google is still recommending you add video descriptions, but if that is too much of a hassle, you should know it is not a requirement.
Google posted this notice in the data anomalies section on May 4th, "The description property is no longer required for Video structured data items (though it's still strongly recommended to help Google better understand the content of your video). As a result, the missing description issue will no longer appear as a critical issue, and you may see an increase in the number of valid Video structured data items in your Video enhancement report."
Forum discussion at Twitter.
