According to a post by "belfast" quite recently, the tune is still used by the BBC World Service. This guy knows what he is talking about, so the tune has not even been dropped, let alone "banned". Where, Mrrzy, did you get the idea that it had been banned?      

Since it's a unionist tune, and song, though the words are seldom sung nowadays, it can hardly be called subversive either.

Problem is, although it was written over a hundred years before the Orange Order was founded, c.1687, it's now seen as an Orange song, and is therefore controversial. To the modern, liberal, mind, the words are racist and sectarian, but they are over 300 years old and revelatory of history.

Thinking nationalists also see it as such and accept it as part of the Irish tradition, though I've yet to meet one that likes the words! Most though, love the tune.