The discussion in bug 895517 is more about whether we should perform this upgrade and be nice about it, i.e., set true or false whether the call was to voicemail or emergency. Discussion with (mainly) julien, etienne and anthony proved that the overall complexity and hacking involved to perform the "nice" upgrade was not worth it, regarding the resulting code. But I think we should anyway upgrade the database, because we are now needing a new field in all elements.