https://www.protocol.com/amazon-headquarters-arlington-office-space
One would think that Amazon might want to build the tallest building on the planet. Certainly the money is there for it. HQ2 will be significantly taller than the Apple_Park complex, but it still won't be that much of a tall building complex.
Amazon's New $2.5 Billion Headquarters https://www.youtube.com/watch?v=Dk3thX_pb5k
How Amazon HQ2 could change Arlington and D.C. https://www.youtube.com/watch?v=Dv5-CH6VewA
Inside Amazon's New Headquarters https://www.youtube.com/watch?v=g6_6FZW19Qk tech World
Key Details About Amazon's Arlington Headquarters | Amazon News https://www.youtube.com/watch?v=vu3jSgKgj-g
Of course almost any building can eventually be repurposed, if need be. So if there is an office surplus there are other options.
An office building in Chicago has become partially residential to become a luxury hotel.
330_North_Wabash was originally built to just be a 52 story office tower. Eventually part of it became repurposed as the-Langham hotel.