The progression is very slight, I'll admit, and they could probably cut it down by at least two episodes. But it did happen.
Isaac is thinking more than just wiping out his enemies and leaving to probably die in a wasteland somewhere. He hates Hector for being a traitor, but based on the conversations he had, he might already be considering what Hector is suffering through to be appropriate punishment. At the least, his concept of life and death have drastically changed, to the point where him summoning Dracula from hell seems feasible.
Hector... well, they're going to kill Carmilla (potentially turning her into a wraith for her canonical appearances). And they knew that the audience couldn't sympathize with her, so the rest of the vampire quad is there. They basically admit they fucked up in the series with the rest of Carmilla's group calling her an idiot for treating Hector that way when he was so integral to her plan.
Alucard is MORE miserable. Which sets up him getting depressed and sleeping for a hundred or more years. I honestly wish the twins had better ties to the series lore and just left him after he taught them what they needed to know, instead of having a big betrayal, though. That would have been poignant. Even if he handles things well, the mortals will be moving on.
Trevor and Sypha are on a more depressed foot than they started, and the cult of Dracula is now established and spreading. I think that's fine considering their impact on the setting is mostly done with the death of Dracula. The cult is the actually important thing from that storyline, since they more or less effect change right up until the final game in the timeline.