For the first part of your post: if they keep the interpretive endings AND add the specific ones that ARE tied to specific actions/choices, thats a good thing for sure.
As for the second part, I've already explained it. Why would all your origin playthroughs lead to a singular end in a game with so many variables? It is akin to watching a movie with an inconsistent plot, where main character acts with poor recognition of the world around them. There are certain story points for origin characters that only include specific options. Let's call those 'big story puzzles', yet story won't be complete until the whole puzzle is complete, the smaller pieces are as vital. And those smaller pieces need to fit with the bigger ones. There might be three specific options to choose at the crossroads, but their interpretation and meaning can shift from one pt to another, based on other, non-origin narrative/choices.
I have to second Anska here: have you played an origin character? Because your answer confuses me. The discussion was whether the origin evil ending fits their character, not whether they only get one ending. The generic evil endings I have seen on yt were from Astarion's origin run, so I assume the other companions get access to these as well. Dark urge might not, depend on the choices you make at the temple, but this is already so in the game.
