The pro-armed forces media are astute enough to know that whilst Puma may not be in Afghan; it is doing/available for; other jobs. Jobs that will need replacing by Chinook should Puma go. ie the concetina effect still equates to a loss of helicopters when said lack of rotary has already attracted bad press.
You are absolutely right - but when that bad press happened, times were much better than they are now, so the average British person had fewer pressing concerns. The Govt might well just decide to take a brief flurry of bad publicity knowing that very quickly people's attention will turn back to jobs/the economy/Olympics/Diamond Jubilee (or, more likely, Britain's Got Talent/X Factor!).
It was my understanding thar Puma 2 will be deployed in Afghan as soon as it comes on line
...but how soon can Puma 2 deploy, and how does that compare with the Govt's stated date from Afghanistan? The Puma 2's first flight was only six months ago, and whether or not the current exit date turns out to be nonsense won't matter, because the decision about Puma 2 will be made long before the exit date officially changes.