I don't think you tease the existence of space dragons and then not pay it off at some point, so yeah I think some of them survived, in fact there's a case to be made the at least nine of them survived. The mysterious Nine have the ability to subvert another's will as we see with their agent Xur (something the Ahamkara were known to be able to do) and the Nine only accept payment in strange coins which could be considered treasure and Dragons like their treasure.