This could mean that video calls can be compressed more aggressively. I.e., just send someone's face once, and then send posture and facial expression parameters for the remainder of the session.

That's a great idea. You could have low latency, high def, high FPS video convos. Couldn't someone launch a plausible competitor to Zoom doing this? I'd certainly prefer that service.

Nvidia is working on it already. https://developer.nvidia.com/maxine

The downside is that we will lose our #1 reason for having symmetric upload/download speeds in residential areas.