I think there were 2 very similar versions that were released around the same time. The one you have pictured does have a zipper compartment in the center.
I have this in the black and it's a great, easily wearable and functionable bag. Don't let one SA's advice sway you-most of us are more on top of the Chanel news than they are!
I have this bag in Black and Red and I LOVE it. Does not slip off my arm like the GST. It really comes down to what you prefer. And your SA is wrong, it is not a dated style