When making changes to annotation symbology a new symbol collection is created and the previous settings are retained and marked as *_Old or *_Old_1, etc. Existing annotation has to be moved to the new ID. When working large volumes of annotation this becomes a huge undertaking before all the anno is moved and you can delete the *_Old symbol collection.
This wouldn't be as bad if the format fields in the anno table were actually used by ArcObjects. Currently they are there only for human interpretation with the actual settings stored in XML as CLOBs deep within the geodatabase model.