I looked into the GatherTextFromAssetsCommandlet.cpp and under UGatherTextFromAssetsCommandlet::ProcessPackages it looks like it only gather’s text from objects if they are of type UBlueprint, UDataTable or UDialogueWave.
This is the code for blueprint objects:
if ( Object->IsA( UBlueprint::StaticClass() ) )
{
UBlueprint* Blueprint = Cast<UBlueprint>( Object );
if( Blueprint->GeneratedClass != NULL )
{
FGatherTextFromObject::Execute(this, Blueprint->GeneratedClass->GetDefaultObject(), Package, bFixBroken);
}
else
{
UE_LOG(LogGatherTextFromAssetsCommandlet, Warning, TEXT("%s - Invalid generated class!"), *Blueprint->GetFullName());
}
}
I took that to mean that the UDataAsset is not supported here without engine changes.