Incorrect. A simple reading of traditional church history will show that the sabbath issue wasn't fully accepted until over 300 years after the death of Christ.
Canon 29 of the Council of Laodecia of the year 365 AD says this:
Canon 29
Christians must not judaize by resting on the Sabbath, but must work on that day, rather honouring the Lord's Day; and, if they can, resting then as Christians. But if any shall be found to be judaizers, let them be anathema from Christ.
So it wasn't apparent that Paul ever wrote about transferring the worship and solemnity of the Sabbath of Jesus Christ to any other day besides the one Christ created holy and kept holy.
In fact it took over 300 years for this to happen...and that was primarily because of anti-Jewish sentiment in the early traditional church.
We see the Lords day worship in Acts “On the first day of the week we came together to break bread,” in the very earliest known Church writing, the Didache, in St. Justin Martyr’s 1st Apology and thereafter. There’s never a time we don’t see it.
Your cite doesn’t mark the beginning, just as Council proclamations against heresies do not mark the beginning non-heretical teaching.
With all due respect, that is absolutely not true. The Synod, was not a council because it was only a local council attended by about 30 bishops and not called by the Pope. Among its declarations was a "canon" or declaration that Christians were to no longer observe both the Jewish (Saturday) Sabbath and the Christian (Sunday) Sabbath.
Peace be with you.