Apple Car Play

I have 2014 Impala LT.
I read that the 15 models with 4LTE do NOT have the apps that were promised as GM is now going down the route to just use Apple and Andorid car play and use apps that way and that people with 4LTE could have software updated added to use apps from phones. What about 14 models why do u need internet car to do this. I use my Bluetooth connection for Pandora and I stream I heart radio and other music apps. Why cant apps be added with USB connection to add app then use phone and touch screen after download?