They already said that the "cut" content is cut because it isn't fitting with what they intended in their Art.
If you happen to like it, too bad (for now).
But they also say they listen to the feedback, and they've been listening to us pretty well so far.
I personally want expansion, not bringing "cut" content back.
Padding out the cursory ending would be very welcome, but for most of the cut content, yeah, I can see why they cut it.
Yep, I don't mind if they added ending slides ala obsidian rpgs (it wasn't a norm to begin with), or perhaps some after the fact mentions of our previous actions just like the Act 2 finale.
I agree with previous poster that Larian has never made an expansion, but I just keep hoping since it's a DnD game, I hope they approach it like Pathfinder and/or Solasta.