We see Izual in front on the Angiris Council (Malthael is absent since he has been roaming the halls of the Pandemonium Fortress for the past 20 years), he is about to be interrogated for the nth time since returning to the High Heavens after being released from his prison in DII. The Archangels talk among themselves, allowing us to learn more about them and helping new player learn a bit about the past events.
Then they turn to Izual and start interrogating him about something (lets say about the Soulstones). It's implied that Izual always remained silent but this time he says "if you want to know x (whaterver the council inquiry was) you should ask him" (pointing to Tyrael), he then go on to expose how Tyrael went behind the back on the Council and interfered in human affairs. This leads to Tyrael being cast out of the High Heavens by the Council. He then falls to sanctuary and the rest of the cinematic stays the same.

What were you expecting?