Since this a purely exegetical question (i.e., it doesn’t really affect a fundamental teaching about Jesus), the Church does not have an “official” position on how to interpret Matthew 1:23.
In this passage, Matthew is simply applying the prophecy in Isaiah 7:14 to Jesus:
Therefore the Lord himself will give you a sign. Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel.
In context, Isaiah is prophesying the birth of Hezekiah, the son of Ahaz. (Hezekiah is portrayed in the Old Testament as a holy and prudent king, unlike his father.) However, Matthew sees that the prophesy has a deeper meaning in Jesus Christ, who is, after all “God-with-us” in a much more perfect way than Hezekiah ever was.
It seems that neither Jesus nor any of his disciples ever used Immanuel as an actual title. Hence Matthew is merely applying the prophecy to Jesus, since it describes Jesus’ condition (as God-made-man) very well.
(As a source for these reflections, I used the Ignatius Catholic Study Bible: New Testament, the notes for Matthew 1:23.)