Great question!
I don't think so, because at this time you still did not have a consolidation of authority and the power of the state to enforce it. Christian bodies were still somewhat free and if Athansius' position on the matter was controversial local and regional churches would have fought against it. As it was his position on the issue of the Canon was accepted because it was consistent with the understanding of Christians all the way back to the Apostolic Era.
I find it interesting that this was all done independent of any Bishop in Rome, or grand council.
Is it possible Rome did not want to take a solid position so they could change their position as their "traditions and doctrines" changed with the times?
firstly few councils were ever held in the city of Rome.
secondly canon was certainly discussed at councils though indeed no specific canon of any specific council declares what is definitlvly IN the Bible though many declared what was right out for sure.
further while athansius opinion is certainly important and relevant I don't see any reason for taking it in a vaccum; all decisions should be made as the whole church not simply as individuals; far to big of a risk there if you ask me.