In what world would a Karlach cure require a reboot?
-Give enhanced infernal iron to Dammon
-"OH cool, I found these Gordian schematics from the Steel Watch!"
- Heart fixed
Where the rewrite?
That specific story-point would be fine. When I was referring to the 'reboot' it was encompassing all the cut content like the zones and their quest chains. I haven't left Act I (may never seeing how it all turns out). So I'm going by what posts are saying, and using some deductive reasoning. Namely, that if Zone content was cut. Then they probably altered quest chains to 'wrap up' sooner.
So, if that content was suddenly added. Then those quests would need to be changed back to the way they were. May never know just how much was altered to fit the 'new' Story Board.
...hence why I believe they'd essentially be 'rebooting' the story likely from the end of Act II onward. Depending on when the cutting start.
And while it's not impossible. I don't see it happening since, from what I've read, not all the cut content was done with the voicing of lines. Which means they'd need to get the VAs back in the recording booth ($$$). Then implement all that into content (Voicing, Level Design, Cutscenes, think they did MoCap too?) that is probably only partially done ($$$$). And finally, try and sell that repackage; hoping it turns a profit.
-OR-
They could leave it 'as is' and move on to the next project.
