While that would be cool, I can’t picture Sanderson doing something like that seriously. That would be a huuuuuge twist, and there’s basically no foreshadowing for something like that. The air pressurization is just because Urithiru is high in the mountains where the air is thinner. How would the tower’s mild air pressure regulator even work in space, there’s no air outside of the tower. The complete vacuum of space seems like it would be stronger than the mild pressure changes we see.
And how would this have even happened? Did the ancient radiants somehow have insanely advanced technology? How would they have developed that while being ravaged by the desolations? Also, Urithiru is full of giant open arches and windows, how would that work? Too many things don’t add up.
Its funny to think about though, the giant city just being yeeted through space.