I'll second the Brake Fluid flush / change here. It is very important to make sure you have good, clean, and enough brake fluid in all vehicles. Brake fluid starts out as an Amber, or light tan color, and can easilly get dark brown or even Black if is isn't changed. Brake fluid is designed to pick up wear particles etc. from the calipers and master cylender, and should be changed about every 3 years, or 60k miles, in my opinion. I change mine every 3 years, as it would take me about 10 years to get to 60k miles.
The rest of the stuff the dealer told you, I'll agree here, in that it was upselling. It didn't hurt your Traverse by any means, but it may not have been necessary yet.