Couple of quick updates from my personal experience.
2017 Camaro SS did NOT have on-screen nav. It only had an option where you call on-star and they set the address on their end and it sends it to the car via voice-enable commands as you drive....very annoying and weird. One dude couldn't spell Cosmopolitan hotel in Vegas and yeah....
2017 GMC Yukon SLT (rented from ITO last weekend) does have full on-screen navigation.