(edit in progress)

So what is so special about East Anglia that it deserves its own geographic DNA project ? 

First consider its location and topography. It is located on the North Sea and with a myriad of rivers and estuaries it affords easy landing to boats from the Continent or Scandinavia.

 The region has historically been a gateway into Britain for peoples migrating from the continent, coming as migrants or invaders. It was that part of this island that connected to Doggerland - the land bridge to the continent - and which persisted for thousands of years after the last Ice Age. Its rivers and estuaries afforded easy access to boatmen. The fenland, once drained, became excellent agricultural land and it was very much the bread basket of England.