Undoubtedly ATNotts, vibes suggests there's a "we've spent money [at EMA], now we need the returns" thrown in there as well - money on things like an extension to the terminal for an enlarged security screening area, before anyone asks. DHL say that they themselves are putting £90m into the EMA hub, so MAG can't be spending so much there. But EMA has chased business such as the LCCs that isn't hugely profitable, and has deployed tactics such as drop off fees, express security lanes, etc to help swell the coffers. Even so, aside from DHL there's not much sign of investment on the horizon, other than more car parks!!!
I think it's sooner rather than later, EMA will reach saturation point on the old faithfuls like Malaga and Palma. BHX has in recent years under served these markets, but the pendulum would appear to be swinging back westwards, to the detriment of EMA
Not so much saturation point at EMA, more that BHX is opening up to LCCs and travelers from their catchment area will increasingly fly local rather than drive up the M42 to get a cheap flight.