If USA, use 1800SAMSUNG to ask now.
Most other places, use the chat at samsung.com
Be aware that the app is from Google and well, not under Samsung's control. The last software warranty I read said apps could change without notice.
I recently bought a Samsung curved tv model UA48J6300AW
before i bought the tv i insisted on the youtube app and i was told it's there, even in the box it showed the youtube logo but i unfortunately i didn't find it anywhere. it's not even in the samsung app store either, so i was wondering is there a way to get or manually install the app on the tv ? thanks
here's the box picture