Blackmail - I see what you mean, I thought you were saying that the test specimen would be stronger than a normal wing so breaking it doesn't prove much. Here's why yes!
As I said before it depends on the failure - for instance an aircraft may have a low Velocity never exceed (Vne) because the pitot tube breaks. Fix the pitot tube and the Vne can be increased - in other words a low Vne doesn't mean a weak aircraft. Similary a failure of an Airbus wing doesn't nescessarily mean a failure of the whole structure. It might be that the flaps broke off so the flap attachment needs further work - rather than the wing box itself - this would of course mean further flap tests, but not nescessarily further wing breaking tests. Without further info it is hard to judge.
Its is easy for Airbus not to incur a delay - bring the aircraft into service with a reduced ZFW, then fix it sometime later. It depends on the cost of delays, versus the cost of a lower ZFW.