Yeah, imagine if a burger chain hyped up by saying "hey burger fans, if you like burgers, maybe you should come see our big mysterious announcement at BurgerCon2018, we think you'll be pleasantly surprised, WINK WINK NUDGE NUDGE" and then unveiled a soup and salad deal.
Somebody would like it, sure, and it might even be a good business move... but that room full of people you coaxed into showing up came looking for meat and cheese, and now feels like they've been snookered.
Especially when they figure out that it's taking the place of any new burgers they'd expected to eat for the next few years.