If Pope Francis is turning the Church from being self-referential towards a new engagement with her objective mission, then Chapter 4 of the new Letter does this with broad brush strokes. He sets the New Evangelisation in relief by the way he refers to the poor of the world and the common good. The social dimension of evangelisation is not an 'add on', but is integral to the Gospel.
Just as we can't speak of personal morality apart from social morality, or the Spiritual life apart from the moral life, or doctrine apart from Scripture or Liturgy, so "to evangelise is to make the Kingdom of God present in our world." Indeed, what will generate new convictions about the need to address all forms of social disfuntionality in our world, if not the Gospel!
So, we can see our mission in a limited way by trying to make converts, when at root what we are actually called to do is to witness to our faith.
Or, we can see our mission as evangelism - a 'one off' announcement of the Gospel, when in fact we are called to communicate Christ at all times and in any way.
Or, we can see our mission as trying to fit into the surrounding culture in a syncretistic way, when in fact we are called to dialogue with the culture from the very ground of truth itself.
No, evangelisation is not an element of the Christian life, but is our primary focus.
(In paragraph 254 in this chapter the Holy Father quotes the Enchiridion Vaticanum. For my part, I don't understand why he put this quote here and would like to see it qualified further.)