In an failed V&V testing portion of a new product could point to many factors such as poor design, test method, test operators or as you suggested a product simply not able to meet a spec. If a root-cause analysis of these failures indicate that the cause of the problem is indeed the spec, then it is early enough in the life of the product to deviate from the intended specs, or as you mentioned a regression analysis can be performed from accelerated aging. This regression can indicate what the actual threshold of the specific product or design spec is. I feel though that even with the regression a spec deviation could be in order.