Yeah, I think we can consider Matthew 16:19 in a few steps:
Our Roman Catholic friends hold that the Keys belong to the Pope as the head of the church. The claim is that Jesus gave the Keys to Peter and to his followers. This idea that the Keys are bound up to the supposed Papal office is not true, for in John 20:19-23, we find Christ giving the Keys to all His disciples, breathing on them the Holy Spirit.
Now, regarding Apostolic Succession, it's possible to make appeals to tradition. But note here, first of all, that there's a question of (1) which tradition, (2) a belief in that the office of Bishop is by divine right, and (3) a belief in Holy Tradition. These are all part of the same thing, but here I'm highlighting three problems in their own right, and all of which have no foundation in the Holy Scriptures. So, to speak simply, we can't find the doctrine of Apostolic Succession in the Bible. It's an idea that developed over time, and it really only makes sense to believe in it if we believe in an Oral Tradition outside of the Bible, which we, Lutherans, don't. That is, we can be certain that the Scriptures are the true words of God, but it's impossible to be certain about what in tradition is of God and what is of man. So, this is why tradition must always be governed by God's Word.
So, we reject the theory of Apostolic Succession, but we do hold to Apostolicity, as we confess in the creed: "I believe in one holy catholic and apostolic Church." And the reason we confess that the Church is Apostolic is that it’s built on the foundation of the Apostles and Prophets, with Christ Jesus as the Cornerstone. It’s also Apostolic given its doctrinal and historical connection with the Apostles, and that it continually sets forth the doctrine of the Apostles, remains steadfast in the teachings, and carries the Apostolic mission of preaching the Gospel to the whole world.
We can appreciate that the early Church rightly stressed the importance of Apostolicity, especially against heretics and schismatics. However, Apostolicity should not be understood as a transmitting of divinely instituted authority or hierarchy, for this has no real Scriptural support, and is in fact, even an idea refuted by some of the Church Fathers.
Returning to Matthew 16:19 and John 20:19-23, then, who does our Lord give the Keys to? He gives them to His disciples, who are the foundation of the Christian church (Ephesians 2:20). So by this, we can understand the giving of the Keys more broadly, namely, that they are given to the Church, and that they are connected with the Holy Spirit, whom God graciously gives us in our Baptism and through His Word. So this means that the office of the Keys belong to all Christians, but especially to the Pastoral office for the public declaration of the Gospel.
Simply, exercising the Keys is to call sinners to repentance and to declare the Gospel of Jesus to the contrite. And this is given to the whole Church, but is also demanded of those who serve in the Pastoral office, whose duty it is to proclaim God's Word.
Many words here, but hopefully this helps!
The grace and peace of Christ to you!