Honestly, I think at this point we might be beating a dead horse. That's not to say people shouldn't keep expressing their opinion on it or anything, but if Larian doesn't realize at this point people find Karlach's ending, even with the new patch 2 content, extremely disappointing, then they're just not paying any attention. Based on what they have said, it's pretty clear they are aware of this, however. I don't think the new content for her actually resolves any of the problems people had with her story- it certainly leaves me feeling unsatisfied- but the fact they felt the need to put something together makes it pretty clear they know there's an issue here.
I do agree it would be nice to get some kind of confirmation that they're aware of the issue and plan to address it further, but I'd be surprised if we actually see significant changes to how things play out until we (hopefully!) get a Baldur's Gate 3: Definitive Edition sometime in 2024. Thankfully Larian does have a known track record of addressing stuff like this in definitive editions, so I'm hopeful it'll (eventually) get sorted.
