You can get WebRTC as a function enabled on the video devices without cloud awareness as it actually only relies on the web client functionality on the endpoint. But you would not be able to use it to join MS Teams or other type of meetings that uses WebRTC as you cannot enable calendar integration without it being cloud aware. As OBTP is the only option for joining this type of meetings and this relies on Hybrid Calendar your options are to use Edge for devices to make your on-prem endpoints cloud aware.
Simple answer is no you won’t be able to join a WebRTC meeting.
AFAIK the only way to join a MS Teams meeting with a Cisco video device is to get the meeting to show up on the device and for that you need to invite the device calendar account and have hybrid calendar enabled. With this OBTP will be presented to let you join the meeting that is in the device calendar.
I’ve seen that video before and as far as I can tell it is using a purpose built macro to join a specific meeting as it’s doesn’t give any option for entering what meeting you want to join. My guess is that it is something that was created just for the demo purpose.
Per all general available information OBTP is needed to join a WebRTC meeting of choice.
