The logic here appears to be more difficult: 

 * PlanningElements will be merged into Workpackages too
 * as this is the case, it is not yet clear, what will happen to the rights: This change gives everyone, who currently has the rights to see issues the right to see both the migrated issues __and__ the migrated plannning-elements. 

My guess is, it is best to leave this out of the migrations: The default-data is sufficient to produce a working configuration, we will need to deal with the migration of existing projects/rights separately.