Troparia, kontakia, akathists and canons have for centuries been composed in good faith, and in anticipation of pending glorification, before a person has been "officially" glorified, including at local level (e.g. by the Greek church, the Russian church, etc). The point which needs to be stressed is that, even if that person is, with time, formally declared a saint, such pre-glorification hymnody must be used only for private devotional use. Any such hymnody must be assessed by the Church hierarchy as theologically and doctrinally sound before it is approved for public, liturgical use. IIRC, all local churches have a body or committee of some sort, made up of clerics and hymnographers, which examines such texts.