You speak right from my mind. This "new ending" feels like some they think that give her a couple brutal cliche (like smoking from nowhere) and pafos just make this end more good. They said that she deserves it... Deserves not be fixed? I`m really wanna know what she doing in her past for deserves this... Maybe something even more evil than
Astarion in "7000 people killing" ending.
And we still have gondians problem and no 3 act (or any act) questline problem. I know it`s need more time for work and release, but why they just dont take more time and add really "new ending that she deserves and make people happy" later? If they are planning to do it anyway - that`s okay, but im betting they just let thing how it is now and forget about Karlach at all.