Microsoft’s justification for the product change isn’t exactly made clear however the features has never really caught on. Microsoft has indicated that only a small handful of customers will be affected by this change and that most of them are currently only in the testing phase. Microsoft has also stated that their decision to remove the feature is related to architectural complications. For instance, the hybrid voice feature required running Lync Server on premises as well Lync Online, but users didn't get all of the voice capabilities. Read the full report here.