en.wikipedia.org/wiki/First_Council_of_Nicaea

Jesus as literal son of god was only established some 400 years later. And when later the records of the gospel got translated through multiple languages it seems very plausible to me, that under the assumption that Jesus should be the literal son of god, this sentence is supposed to be worded to confirm that. It is as easy as forgetting a half sentence like “HE said” or turn a third person into a first person form. Or to loose the context that he was announced already before Ibrahim etc.