The Terminal will be built irrespective of whether MAG owns the airport or not. Airports in the UK are money making machines so long as they can process passengers and freight.
MAG bought BOH from National Express who having purchased from the council for almost no money, made a huge profit from the deal. MAG bought EMA which is what they really wanted... MAG got BOH as a part of the deal - almost a buy one get one free arrangement. Since then MAG has taken BOH ownership seriously and has approved investment in the new terminal.
A read of this interview gives some clues to MAG strategy and rationale.
http://www.guardian.co.uk/business/2...ansportintheuk
Even if MAG were to sell, there would be investors from Spain, Australia and elsewhere lining up to buy, because of the money making machine characteristic of UK airports.
Any airport asset is driven by the runway and operating license. A bit like a piece of land gaining value when it has permision for building. Passenger airport licenses in the UK are rare and valuable.
BOH has a decent licensed runway in the south of the UK. Because of slot availability elsewhere (basic physics - only about 40 movements max per hour is feasable per runway) BOH will see double digit growth annually at least until additional runways are built to serve London.
The new terminal will happen, delays to infrastructure projects are commonplace (Dubai Terminal 3 is two years late already) but no reason to doubt the programme. Key clues are planning permission and a public statement from MAG that they have committed the investment.... and the fact that have the former infrastructure has been knocked down!
It's the runways that the airlines need, the terminal is important but secondary - even LHR uses tents sometimes! But without the runways you have nothing more than a shopping mall.
Airport owners think like landlords, ie. how can they make the most profit from their investment.
FF