One of the things that changed was the direction from which persecution came.
Just prior to the Jewish rebellion, or as it was reaching the boiling point, Rome became the chief oponent of Christianity.
Prior to this it was mainly the Jews. Not exclusively, but on the main. Gentile persecution (based on the book of Acts) was often at the instigation of the Jews or was directed at the Jews with Christians considered a part of the Jewish problem.
Some consider Jesus' words at Luke 21:24 to refer to this change in the direction of persecution, since historically it's start basically parallels with the Jewish war. The phrase I am referring to is, "and Jerusalem will be trampled on by the nations, until the appointed times of the nations are fulfilled." With "Jerusalem" basically alluding to Christianity rather than the Jewish city. With this understanding, Jesus is saying that from that time onward they could expect persecution mainly coming from Gentile sources until Gentile dominion comes to an end.
This is not quite the same as the way the Society applies it. In their commentary on this phrase they insert the words, "continue to" after "will" so as to make the allusion a reference to the continuation of Gentile domination over Jewish (i.e. Theocratic) rule since 607 bc.