That's a url to Stream (Classic). It is an M365 Group. However I don't think that Stream (Classic) supports dynamic groups, or at least we never did any work to support it. So if it works there could be bugs or cases where it doesn't.
That being said we are in the process of retiring Stream (Classic). We likely will announce a retirement date later this year and give 12-months notice before it's shut down.
Our go forward solution is Stream (on SharePoint), which is to just upload your videos directly to SharePoint, Teams, Yammer, and OneDrive.
So if you make a SharePoint team site based on a unified group and make the group dynamic, everyone in that dynamic group will have access to the site and all the video files.
