Yes, because there was no Roman Universal Church in the time of Constantine. It was just the Church and the institution precedes Constantine.
If you mean to say that the Council of Nivea is a corruption of the true Christian teaches then you are also saying the Orthodox and Protestants are corruption true Christian teachings which makes a special snowflake who thinks he knows better than the Apostles, the early church fathers and countless theologians of said sects. In short....a retard.