In short, the argument put forward by Prof. Feldman is interesting but unconvincing. The data does not require the hypothesis of Eusebian composition in order to explain it.
It is an interesting article and one that should be read.
BTW, Origen knew of the section, although we don’t really know what the section said in Origen’s time:
I would like to say to Celsus, who represents the Jew as accepting somehow John as a Baptist, who baptized Jesus, that the existence of John the Baptist, baptizing for the remission of sins, is related by one who lived no great length of time after John and Jesus. For in the 18th book of his Antiquities of the Jews, Josephus bears witness to John as having been a Baptist, and as promising purification to those who underwent the rite. Now this writer, although not believing in Jesus as the Christ, in seeking after the cause of the fall of Jerusalem and the destruction of the temple, whereas he ought to have said that the conspiracy against Jesus was the cause of these calamities befalling the people, since they put to death Christ, who was a prophet, says nevertheless— being, although against his will, not far from the truth— that these disasters happened to the Jews as a punishment for the death of James the Just, who was a brother of Jesus (called Christ),— the Jews having put him to death, although he was a man most distinguished for his justice. Paul, a genuine disciple of Jesus, says that he regarded this James as a brother of the Lord, not so much on account of their relationship by blood, or of their being brought up together, as because of his virtue and doctrine. If, then, he says that it was on account of James that the desolation of Jerusalem was made to overtake the Jews, how should it not be more in accordance with reason to say that it happened on account (of the death) of Jesus Christ, of whose divinity so many Churches are witnesses, composed of those who have been convened from a flood of sins, and who have joined themselves to the Creator, and who refer all their actions to His good pleasure. (Ad Celsus 1.47)
Anyway, a positive read.
I do not believe Josephus who made his career calling Vespasian God’s chosen person called Jesus Christ. However, the TJ does have some historical foundation… just not sure how much.
On the other issue… would this prove a Historical Jesus? No. In my opinion it wouldn’t prove a historical any more than a lack of the TJ would disprove the historical Jesus. TJ still falls into the realm of historical reporting. Josephus was not an eyewitness — and given his lack of reference to any of the Way/Jesus movement in Wars, I’d say he would have to have it reported to him via several degrees of separation.