I think we're well past the point in this community where use of the word "literacy" is helpful in communicating one's meaning. It is a crutch, a cliche. If everyone would stop using that word we'd be forced to be more clear about our ideas.
Phrases like "new literacies," "digital media literacy," or "21st century literacies" don't really mean anything. If "literacy" was removed from the lexicon, people would be forced to come up with more specific ways to express themselves.
And we'd also get rid of annoying redundancies like "writing literacy." "Writing" is just fine, thank you.
Also, the whole habit strikes me as self-defeating, because traditionally, only early elementary teachers think of "literacy" as actually being their job. High school English teachers, for the most part, know nothing about "literacy" and don't want to.
Of course, a new word would have to be invented to describe the ability to read and write, but I think the inconvenience would be worth it.
If you want a better framework for understanding reading, writing and the discipline of English, you need to read Textual Power: Literary Theory and the Teaching of English, by Robert Scholes.