It appears to me that the English, never living through the 50-years-longing depression called Helvetica, have now awaked and miss something.

…never living through the 50-years-longing depression called Helvetica …

Sure, there was a lot of Gill Sans, but Univers and Helvetica (aka Standard) were well used.
I took these photos in London and East Anglia in 2005:
http://typographica.org/on-typography/the-helvetica-meditations/

Gotham at least makes a little bit of sense...given it's urban inspiration.

More logical explanation...they are all the same developer and/or they are all using the same design/PR/marketing firm?

In my town they haven't caught up with Gotham.
It's either Trajan or Copperplate. An awful lot of
copperplate. I have no idea why.

Perhaps they all use the same design/PR/marketing. They are not the same developer though and 3 of them are in competition with each other, they are luxury residential buildings.
The architecture of the four projects is also quite different.

Two of the identities are also similar in that they take some inspiration from the architecture. The Harlequin tower fills the Gotham strokes with a pattern of trusses, a motif taken from the architecture. And the Neo Bankside project apart from using Gotham uses another typeface with chamfered corners which also alludes to the structural elements of the building, designed by Richard Roger's office.