same for direct access by champ.value

app/models/types_de_champ/drop_down_list_type_de_champ.rb

@@ -1,17 +1,4 @@
 # frozen_string_literal: true
 
 class TypesDeChamp::DropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBase
-  def champ_blank?(champ)
-    super || !champ_value_in_options?(champ)
-  end
-
-  private
-
-  def champ_value_in_options?(champ)
-    champ_with_other_value?(champ) || drop_down_options.include?(champ.value)
-  end
-
-  def champ_with_other_value?(champ)
-    drop_down_other? && champ.value_json&.fetch('other', false)
-  end
 end

app/models/types_de_champ/multiple_drop_down_list_type_de_champ.rb

@@ -24,7 +24,7 @@ class TypesDeChamp::MultipleDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampB
       [champ.value]
     else
       JSON.parse(champ.value)
-    end.filter { drop_down_options.include?(_1) }
+    end
   rescue JSON::ParserError
     []
   end

spec/models/concerns/dossier_rebase_concern_spec.rb

@@ -449,7 +449,7 @@ describe DossierRebaseConcern do
           tdc_to_update.update(drop_down_options: ["option", "updated"])
         end
 
-        it { expect { subject }.to change { dossier.project_champs_public.first.to_s }.from('v1').to('') }
+        it { expect { subject }.not_to change { dossier.project_champs_public.first.to_s } }
       end
 
       context 'when a dropdown unused option is removed' do
@@ -495,7 +495,7 @@ describe DossierRebaseConcern do
           tdc_to_update.update(drop_down_options: ["option", "updated"])
         end
 
-        it { expect { subject }.to change { dossier.project_champs_public.first.to_s }.from('v1, option').to('option') }
+        it { expect { subject }.not_to change { dossier.project_champs_public.first.to_s } }
       end
 
       context 'when a dropdown unused option is removed' do