I think a key thing to note is that this future is taking place when nothing is left EXCEPT for the Adulterine Castle. All the days have run out already. So the two ways to read this would be the world has ended, but the Adulterine Castle is still chugging along and the PC comes to the castle to properly close the curtain on the universe. Or, in true tower form, the Cat has watched the world come to it's close, and you walk in and restart it. That reading fits with the tarot card far better than the other and I think I like it more.