Does Acts 15:21 assume new believers would learn and follow the law from synagogues on sabbath?

Acts 15:19-21 (NIV, Emph mine) > 19 “It is my judgment, therefore, that we should not make it difficult for the Gentiles who are turning to God. 20 Instead we should write to them, telling them to abstain from food polluted by idols, from sexual immorality, from the meat of strangled animals and from blood. **21 For the law of Moses has been preached in every city from the earliest times and is read in the synagogues on every Sabbath.**” This verse is used for and against observing law. Seems like this could mean either, "There are enough people following Moses and observing the law, so no need for more people to follow the law." or "The law is repeated in synagogues and new believers will go to synagogues, so they'll learn and follow them later."