It is actually quite relevant. Romans 2:14-15 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
15Which shew the work of the law written in their hearts, their conscience also bearing witness, and
their thoughts the mean while accusing or else excusing one another;
Before God gave the law to the Jews, Gentiles already had Hammurabi's code, Code of Lipit-Ishtar, Ur-Nammu code, Laws of Eshnunna. True to what the God says in these verses of Romans that the gentiles became a law unto themselves because some of God laws were already written on gentile hearts.
While these man made codes were in no way the perfect law of God they did contain things that are in the law. Rome is an example of how God used ungodly Rome to keep his law. The Punic wars Rome faced off with Carthage. Rome had a problem as gentiles with child sacrifice and used this amongst other reasons to declare war on Carthage in the Senate.
Carthage worshipped Baal Hammon or Baal Ammon. With the god of Ammon being Molech. God used ungodly Rome and their repulsion to bring an end to this lawless practice. When the Apostles met they found that the gentiles needed to only follow don't eat blood, things that are strangled, and abstain from adultery'. I would find that they only had to touch on that because living under gentiles they were well aware of what laws of God were already written on the hearts of gentiles.
I Corinthians amongst other things is Paul giving commandments. Read the whole book and you will see that God is giving commandments through Paul. Which Paul boldly says that fornication such as was found in the church was not even found amongst the gentiles in chapter 5. Paul gives commandments on civil cases such that we are not sue each other in court. Rules on marriage, our body is the temple of God amongst others.
When God parted peoples at the tower of Babel. Gentiles went and formed nations and codified laws that were written on their heart. Some of which were Godly and just and they became a law unto themselves as we find that they already had some of the vary selfsame laws God gave.
When God parted the peoples and they became nations. God in the next chapter he chose Abraham to make his personal nation one that would bear his name. He chose a people that were of no esteem, they were stranger's, peculiar, no people at all. He chose this to be his kingdom.
He gave laws unto his kingdom making it a contract between him and them. They failed, God came to the world and walked amongst us in the flesh and he made a new contract one where he would take alien's and strangers, peculiar people of no esteem and he would make them his kingdom. In the old contract it was made between God and man and God made the highest that man could give the governing law he was to love God with all he was and love his fellow man as himself. The new contract is made between God and God and the governing is the absolute highest because we are to love as God does.
So it is very relevant that he is a gentile and he keeps already those laws of God that were written on his gentile heart and the new ones that he and all of us continue to learn so we can love like God. Which God made possible because all things are possible with Christ and God indwelt in us. Which in the end we are neither gentiles or Jews we are all in Christ.