How is Jesus God's final word? (Protestant Perspective)

The Youth Catechism of the Catholic Church states plainly (emphasis added): > In Jesus Christ, God himself came to earth. _He is God's last Word._ Indeed, some modern English translations of the New Testament present Chapter titles for Hebrews 1 that echo this sentiment: _God's final word: His Son_ (NIV), _God's Final Word in His Son_ (NASB), _God's Supreme Revelation_ (NKJV). Hebrews 1:1-2 says, > God, having spoken earlier at many times and in many ways through the Prophets, spoke to us in these last days by the Son, who he established heir over all things and through whom he made the ages. From a _sola-scriptura_ protestant perspective, what does it mean that _Jesus is God's last word_? Has God spoken to man in the time since Jesus' teaching? If so, by what method has he done so?