Well - slow work day.
I am going to speculate.
We know from the last ep that the original vamps know that the pack of idiots are tracing their bloodlines.
Did Stefan get an extra dose of stupid in his morning coffee? I don't know why he just divulged the info to Klaus. He could have just said that Alaric was being special and they were trying to pry out the stake info - end of convo. He let a valuable piece of info go for no reason. Who is to say that the Originals knew that their death would cause the deaths of those they created?
Up until Finn, only Mikael had been killed. Based on who he was, I doubt he turned anyone. Stefan and Co. had a front row seat to Sage and her lackey's death. That does not mean that Rebecca and the brothers would necessarily know.
None of them had died. So, they would be unaware of any consequences.
Kol should grab Jeremy and vamp him. Because, I would say that bloodline runs back to Rebecca or Klaus. (I would love it if it were Elijah, but I doubt the show runners love me that much.)
Also, what about Tyler? Yes he was vamped by Klaus, but he was already a werewolf by birth. Perhaps the end of Klaus would only end the vampire part of Tyler? (Granted we know that wolves that were not turned properly died, but who is to say that the sire going away would mean their deaths?)
I pity Rebecca but she also annoys me to no end. I would not care if she was the one who died.
Kol irked me at first, but his last outing was better. I would vote to keep him, because he is an unknown. Why kill a character we know so little about? Finn was just a plot device so no big whoop. However, introing people just to kill them is just annoying. Are we going from red shirt hybrids to red shirt originals?