Thats a good point, and it crossed my mind too. The only thing I can assume is that the IoD was painting with a broad brush and that it probably didn't differentiate or consider the matter in too much detail - certainly beyond the principle of not shafting the troops under any circumstances.
I don't think you have grounds to worry.
You
would have grounds to worry if you were a civvy and if you turned 50 after April 6th next year.. the date that HMRC decided you would have to wait a further 5 years before drawing any civvy pension. I spoke with a woman this week, whose Powergen pensioned husband is 50 on.. (I kid you not) April 6th 2010.