To all those who joined me in this morning's Live Event, I wanted to respond to a question here, as promised:
To the question of whether you could join a Live Event via phone bridge, looks like the answer is No. There isn't a phone number generated for the purpose of being used as an alternative to connecting via web and/or Teams client.
Given that the phone bridge scenario is often used as a friction-less, non-techie way of joining calls/events, at least we know that someone only needs a web browser to join and get audio/video, and doesn't need the full Teams desktop client, or some other software install. They could also join via mobile app as well.
Hope that helps!