I uploaded a video to a slide background and found a few issues. When I play the preview in the right hand UI, I can see the video play. However when I preview the slides or play the presentation, the video does not play.
There is also no controls for audio, so unclear if a video contains audio if it will play automatically or if audio is automatically removed by default. However being able to control which is the still frame, the audio controls, and trimming the video sequence would be preferred.