Alright, so he hadn't abandoned his teammates to die before this chapter. But he has abandoned Team 7 and he has tried to kill members of Team 7. Even if he didn't follow through with it. And the difference between the Killer Bee Arc and the Hokage Summit Arc would be that his revenge target is nearby, and the main focus of their mission, for only one of those Arcs.
Sasuke only tried to kill Naruto because he was suffering from the adverse mental effects of the Curse Seal during the Valley of the End. He regained his lucidity and sanity and chose not to kill Naruto and awaken the Mangekyou Sharingan the way Itachi did.
When Team Seven saw Sasuke the first time during the time skip, I wouldn't consider his performance in front of Orochimaru as anything close to the truth, since later on he reveals he was only using him and he not only betrayed him, but absorbed his power for himself to boot. Anything he did for/with Orochimaru should be taken with a grain of salt.
This is definitely a new Sasuke we've never seen before. He's never been this dark and cold hearted. When he was the leader of Team Hebi, he made it a point NOT to kill his opponents. When he trained with Orochimaru, he made it a point NOT to kill his grunts. He was compassionate and merciful. Now, he's a cold hearted killer. Sasuke has fallen pretty far now.