Here is the official illustration on the MAN website of the Airport City:
And my interpretation looks like this:
I don't think there is other limitations to the height of the building other than local regulation since the distance from centre line of the northern runway is so great. Much more interesting I think is the new T3 pier extension to the east and the new apron (blue area). We can not see the end of the pier to the east, but it seems like the Airport Hotel have to close in the future. Another item of interest is the airside connection between T1 and T2. Then we can look forward to an around 1.2 mile airside walk from the western end of T2 to the eastern end of the new T3 pier. The new connection will add to the flexibility of the airport operation - and with that we may see the end of airlines only using gates at one specific terminal.