Quick reply and iPad

I have public beta 2 installed on my iPad 4th gen but I'm not able to get the the quick reply functionality demonstrated in the keynote (access to the full message thread) working. When pulling down on a message notification while my iPad's is unlocked I am only given the option to reply or cancel, and selecting reply will jump me into the messages app rather than opening the conversation within the notification.

Does anybody know whether this functionality is limited to the iPhone, newer devices or maybe not working at all in the current betas?