My guess is that a money-saving gamble didn't pay off. Presumably Opel (parent company) tried to utilise smaller, cheaper connectors that weren't quite up to the job and this was the result. But hats off to Vauxhall/Opel for doing the recall.
A number of years ago my folks had a 2002 Passat on which the brakes would fail from time to time in (very) cold weather. Not nice, you're approaching a busy junction to join the A9 and the pedal would be solid- no movement at all. The car was back at the main dealer several times, each time coming back with 'No Fault Found'. Well d'uh, a workshop is a tad warmer than the A9! A very quick Google search revealed this was a common fault in colder climes caused by moisture droplets feeezing in the brake servo - and easily cured - but VW and their dealer refused to acknowledge this (probably for fear of claims) having repeatedly sent the car back out on the road claiming it was safe.
VW eventually issued a statement blaming the OWNERS! Saying that owners had allowed dead leaves etc. to accumulate in the plenum chamber thus leading to the moisture issue. But no recall? Needless to say that was the last VW Mum & Dad ever bought.