Hi
As Shabana Sohail said, you cannot directly batch upload videos from Teams to Stream.
You can only download the video files in Teams first and then upload them to Stream one by one.
To get this feature more quickly, you can send a feedback directly to Microsoft to add it in future updates.
To send a feedback in Team you can select the Help button at the bottom lower-left of Teams and then choose Suggest a feature or Give feedback to tell to Microsoft what you think.
Many features of our current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future.
Thanks for your understanding and support.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.