Hi Pallas, I moved your question to our Jive Training and Support Resources space so it gets more visibility. I believe the answer is that you can bulk upload files, which could include videos, but they would not appear as a video object in Jive. If you want to add a video and have it be uploaded to the cloud video service, which involves the encoding & hosting process, then you would be limited to one video at a time.
Uploading the videos as files may work, but they won't get encoded as native video objects. Does that make sense? You can test by going to Create -> File, and then drag & drop multiple video files into the upload window.
Kade is correct. For Jive Cloud 2016.1.x, there is currently no way to bulk upload videos and have it encoded and created in Jive as native video objects. If you were to use the existing bulk upload feature, it would create the videos as attachments to Jive documents instead. This would be useful if you simply wanted to create content that users could download, but it won't be useful for playback.
If this is an important feature you'd like to see in the future, I would encourage posting a feature request idea to the Ideas for Jive space to help capture this use case and feedback for our Product Team.
I hope this helps. Please let me know if you had any other questions on this.