That is something to ponder . . . . I can't say with certainty that the tower is or is not designed for additional floors. If it had been I would have expected to see details in the drawings calling for reinforcing bars to extend above the top of the highest floor slab so columns could be properly connected in the future. There were no such details. Logistically it would be difficult at best. The top three horizontal bands of glass shown in the rendering are screen walls - open to the sky - with steel support structures inside them. It would be difficult to remove those areas of glass, and the supports, to build above.
Since you mentioned your interest in buildings designed to be expanded up, I offer this project in Chicago as one of interest.