I used to post in here a lot back in the day, but stopped due to the off-topic 'banter' - not that should make a difference regarding my opinion (though perhaps says a lot about the community at the moment). What you're suggesting is that the focus of News and Deals be taken off-site to a Steam Group that people have to ask to join. Sure it'll be cross posted in the Steam Community thread, but will be lost in the shuffle off off topic 'banter' (which I'm guessing will increase because 'Hey check the steam group if you want news').
Really it should be the other way around. If you like the personalities in here, you should really befriend them on Steam and perhaps have a group you can chat about daily stuff. Hell I do that now.
I made friends with various people from Steam Community over the years and most of us hang out in a big Steam Chat Group and talk all the time - MetalMurph, Doc Shananigans, Jaja, Xelios, almostheathen, Priit, Mav, Dunder, Steel, Dice, Chuck, golem, grav, Knight, and so on we chat about games, life, and joke constantly. Now imagine we did that in here and added to the off-topic 'banter' rotation, this place would become even more of a mess. However, we know the place for it and keep it within the Steam Group. If we see Gaming news and Deals we like we drop a link the group chat and everyone knows about it. Simple and it works well.
The way you're suggesting is something that would work for YOU. Those who want news go 'off-site' so they find it straight away and you get to keep your friendship groups within Steam Community thread. Perhaps I'm reading it wrong, I don't know.
That's because a lot of them have gave up on this Community ever changing to be blunt. Of course, my opinion differs from yours so naturally I'm trying to create drama. Of course.