[LikeHamilton]

I suspect that HHS will quietly by up properties south and/or east of the hospital, demolish and develop the new lands. Or they will develop their vast parking properties to the west and south west of the hospital. I don't think they will go north of the tracks. They will want to connect the building either above or below the ground.
They may do all of the above.
I imagine there will be private developers starting to pick up lands in the area to hold and sell to HHS to make a profit. The best would be if they start to develop their own project with a higher density projects.
I have been to a few cities and Charleston SC comes to mind with a large hospital and medical research facilities all together in the core area. They are very vibrant areas with lots of housing, shops and restaurants.