It sounds like they're trying to sell you on the 'all wheel drive' not the 'all weather tires' as what will keep you from needing snow tires. You can pretty much only buy a car with 'all seasons' on it so they don't really need to sell those to you.

If they're trying to say 'with AWD you can save money by not buying/swapping snow tires each winter', well, that's really debatable. As many have said, the Subaru AWD will drive OK in bad conditions as long as the all seasons have tread... but dedicated winter tires will still be an upgrade in a variety of ways. Maybe you can get away with not putting snows on a Subaru when you basically HAVE to put them on a 2WD sedan... maybe you can't... but I would not take the salespeople at face value on this.

I know I personally drove a Subaru for years with only all seasons. It was better than a Honda Accord with all seasons, because I wouldn't get stuck on hills, but nowhere near as good as a Subaru with Winters which wouldn't sideslip... and stopped in time.