We must face the possibility that the abbreviated signaller's English used for texting & tweeting, however useful in context, has a malign influence on linguistic development. The ability to choose words with appropriate connotations to express, accurately and concisely, shades of meaning and attitudes is not developed if telegram-writing is the preeminent mode of communication.
If this is true (and it probably is) then not only History but other humanities including language and literature should take priority.
Children will learn to 'tweet', only too willingly, in their own time. School exists to transmit skills and knowledge that children might not otherwise acquire.