Again, would prefer a fix quest for Karlach in the base game. But coming back from Avernus and chilling with friends would be very welcome.
Pretty much how I feel. A more thorough fix to the way her story is written would be ideal for me, but I think a more substantial epilogue like this info hints at might be the best we get. I'm not really familiar with how Larian works since BG3 is my first game from them, but it sort of seems like the level of rewrites/extra content specifically for Karlach that so many people around here want is rather well beyond the scope of what you'd expect pretty much any developer to do, especially post-launch.