I would imagine the gates would all be narrowbody ones, there are plenty of large Widebody gates on the north side of Pier 2 and all of Pier 3, as well as some for 'smaller' ones on the south side of Pier 2 (767, A300, A310).
I guess EZY can move all of their domestics southwards once the Pier is ready, although in the pdf by LGW they stated that for EZY to fit into one terminal DY, ZB, TCX and EI would all have to move northwards. I assume VS are ok down South as by the time their A/C start to arrive their are normally a few gates free from departing aircraft.