The pyrotechnically activated O2 bottles would have a certified lifetime beyond which they need replaced, but they evidently wouldn't be tested in the mean time as they are single use by design. There are several far more dangerous pyrotechnic agents on board passenger aircraft - none of those ever caused a problem to my knowledge - such as flares in the survival kit, and some escape slides/rafts have chemical agents to inflate them. I wouldn't get too excited about the activation mode of the bottles. But the failure rate and subsequent cover up by Boeing management AND the regulator, well, that is an entirely different story!