It hasn’t been left out entirely but with a multiplier of 1.0 it’s not noticeable!
Parts of the building have nothing to do with the Thralls!
240 hours count for both. But they are independent!
You can delay it a little with the Thrall Pot!
Why some people’s thralls are gone is quite simple. The Thralls have 240 hours and only the building parts have been increased to 480 hours! If there had been something in the Thrall Pot we could have delayed it a bit! Everyone has to know for themselves and everyone has their own opinion.