Well, yes on a superficial level that's what Paul might seem to be saying. But he's actually making the larger point that in terms of worship and salvation that there is no difference between any of these.
Gal 3:29 And if you are Christ's, then you are Abraham's seed, and heirs according to the promise.
And who does that "promise" pertain to?
Rom 9:4 who are Israelites, to whom pertain the adoption, the glory, the covenants, the giving of the law, the service of God, and the promises;
Eph_2:12 that at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world.
Again, the new covenant is ONLY with the houses of Israel and Judah.
Now I know the point you're trying to make. You're trying to say that Christians who were once gentile are "gentiles" and thus are not held to the same standards as Jews therefore they don't have to do anything that God said before the book of Matthew.
Is that about right?