Not so sure I agree. The resilience factor is more about why people fly rather than who they fly with. The MAN market is very leisure orientated and very UK focussed - majority being UK residents flying outbound for holiday and VFR. Therefore any UK factors that impact disposable incomes and discretionary spend in the MAN catchment will impact. True is same to an extent at all regional airports. London, including STN, benefit from a much larger share of inbound travel and so they are more insulated from UK specific factors. Nowhere is really immune from the type of geo-policitcal events such as the 2008 financial crisis.
I also think the criticism of the forecasts were fair. The numbers were initially to influence a very controversial planning application for R2 and so were more than just a regular round of DFT / Govt planning. I see no difference between the R2 campaign and the current round of posturing between LHR and LGW and so can't help but see the irony when folks representing MAN get agitated. Remember a well that part of the R2 campaign was to make the point that the traffic that would be attracted with a second runway was of a nature that could't be satisfied at other Northern airports. The fact that the airport has now gone after EZY and RYR (at the expense of other Northern airports) is also not without irony.