I wonder if that "theatre experience" would be a significant improvement for most people. I already do this with friends remotely by jumping on discord and hitting play on whatever service we're using at the same time. There more more automatically in-sync solutions out there for sure, but I can't see doing this in VR being more than a novelty that wears out after a few sessions.

You should actually try it before coming to that conclusion.

The main difference between discord, zoom or any other flat viewing experience vs VR is immersion. Words don’t do it justice, you have to experience it yourself.