It's a damned stupid idea. Where is the fail safe in projected displays vs a window? It's bad enough having crippled flight controls and limited instrumentation following severe electrical failure, but to be completely blind?
As for the idea of a cockpit in the base of the fin, two major issues come to mind. 1) how do you pressurise it without a blow out? 2) the translational movements of the pilots' seats will conflict with their rotational movements and the visual elements, creating disoreintation and CFIT events.
Only an amateur engineer could come up with such folly. It shows how little input pilots have at Airbus. God, how I hate their aeroplanes!