There are cases where A/B testing does not make sense (not enough users to measure anything sensible, etc.). But if the A/B test results were inconclusive, assuming they were done correctly, then what was the point of launching the underlying feature ?

As for the HIPPO pushing for an A/B test because of lack of confidence, all I can say is that we had very different experiences, because I've almost always seen the opposite, be it in marketing, search/recommendation, etc.