Does anyone know why this has not happened?
@rupertclayton

This overlooked taxon change is one of several for North American species in the subfamily Campanuloideae to reflect Morin 2020 and match POWO. It possible that this change will cause ID disagreements (e.g. a genus-level ID of Campanula, which previously would have supported a more precise ID might now be treated as disagreeing with species-level IDs such as Palustricodon aparinoides or Smithiastrum prenanthoides.

It is not feasible to construct atlases for each species within Campanula to enable a split of the genus. Therefore, I will endeavor to review these observations following the renaming of these taxa.