From what i understand, they don't address ratings, just player movement.
However, it would be nice to be able to force trades for your team, and others, and to edit ratings mid-season in Be a GM.
That way if someone is having a breakout year, you can edit your game to go along with real life.
Or, you can make trades between teams, and your own, to make the NHL at the trade deadline look like the one you're playing currently.
It would make a nice change from seeing the trade deadline every year and thinking "That would be cool to play against" and not doing it.
I would love to go against the new and improved Nashville in my Be a GM mode, but unfortunately, i would have to restart and wait for the roster update to do so.