If that broadcaster is Sal then he’s sharing Sports Logiq data that goes beyond some of what is usually discussed here because that company tracks it own data. (Some guys do track their own macro stats as well, for example JFresh uses the micro stats tracked by Corey Sznajder.)
The basic usefulness of Corsi and various XGoal models is that they do a way better job of predicting future offense production than past offensive production.
This is an article from 2017 discussing how Corsi was becoming less predictive, likely because teams adapted to what the analytics told them was getting their ass kicked. That’s the story of all analytics in sports.
www.sportingnews.com
Here’s a short article about expected goal models vs Corsi.
There are introductory articles on hockey analytics.
There are a papers on the internet discussing all sorts of interesting subjects related to hockey analytics. (Way more detailed than these articles.)
There are books on it.
If you want to get to the meat of what’s getting done then go out and discover that. You aren’t going to figure it out by thinking about what you know now and extrapolating personal theories on what it can or can’t do.