This may be due to some conspiratorial spin, but I have to ask it anyway.
You'll have to help me out here. I'm months away from submitting a PhD dissertation related to the Arian comtroversy, and I've never heard a suggestion that Josephus has anything to do with it. Nor the development of the NT canon.
So where's this idea coming from? Then i can give you what I suspect will be a critique of it.