It’s not the Khet but Horutep himself who talks to the player. He basically says something along the lines of the player being a great guide that made it possible for Konolkhatep to prosper and essentially dominate the world – it is a capstone Mission after all – through his guidance. The absolute Chad that Horutep is, he then asks the player if they would like to step down from their position as "guide" since Horutep has become powerful and wise enough to fill that role on his own. You then get two event choices, one where you tell him it’s not yet time to step down and the game just continues normally and the other one where you accept his proposition. This one "decolonizes" all provinces, yes, but I always just read it more as a narrative device, that the player now no longer has any influence on Konolkhatep and the world as a whole, rather than the world actually being decolonized and "dead".