Paradox number one. The first generation to grow up with Google (dob 1998), isn’t necessarily net savvy. Members of this generation still have much to learn from those of us who grew up when golfball typewriters stalked the earth.
Paradox number two. The generation that has grown up with mobile telephony (Vodafone dob 1985), doesn’t know how to use the phone. Sure, everyone can dial a number or send a text message. What several employers have told me is that there’s a time to send a letter, a time to email, a time to text and a time to contact someone by phone (in real time) – and students still have to learn about this. But how do you teach it?
PR Studies 
I don’t think you can, deciding what method of communication to use comes from experience and varies with every different situation, client, journalist, political outlook etc…
I would agree that you cannot teach this…but surely someone wishing to be successful in PR should have a natural instict when it comes to the appropriate way to communicate??
Of course you can teach people about the use of appropriate communication methods. No-one has “natural instincts” about appropriate ways to communicate as the only method we inherit as babies is to emit a loud scream for attention. Similarly, although communication is situational, increasingly in teaching PR we are reflecting a post-modern perspective that there are no simple rules to best practice. We need to equip students with skills in all the communication tools they need, and ensure they are able to determine which is most appropriate at any time. Case studies, role play exercises, reflection, cultural understanding, and work placement all contribute in building such abilities.