Chugalug,
Pretty sure this only applies to 'other ranks' as the scheme was only open to them. Of course those commissioned from said ranks potentially have liability.
When you remove the officer cadre and junior pers for whom this has not been applicable, 2000 folks is a fair chunk of the serving NCOs numbers if that's how many letters went out.
I presume for those that have left it is simply written off? Or will they be going for pensions and billing those happily elsewhere I wonder. This debacle doesn't effect me but with a call for more effort against ISIS and typhoons heading east it's hardly a morale booster for what is probably the cost of yesterday's hellfire and brimstone shots.