[Answered ]-Distinct values on annotated field ArrayAgg using Django 1.11 and PostgreSQL

You can use the StringAgg function to get the distinct uuids and then leverage you serializer to split the string and convert it to list of uuids.

class InterestStatusViewset(viewsets.ModelViewSet):
   queryset = InterestStatus.objects.all()
   serializer_class = InterestStatusSerializer

   def get_queryset(self):
      qs = super().get_queryset()
      qs = qs.annotate(
        annotated_interested_uids=StringAgg('interested__account__uuid',',',distinct=True),
        annotated_not_interested_uids=StringAgg('not_interested__account__uuid',',',distinct=True),
    )
    return qs

Serializer can be modified as below to get the required output using SerializerMethodField

class InterestStatusSerializer(serializers.ModelSerializer):
    interested_users_uids = serializers.SerializerMethodField()
    not_interested_users_uids = serializers.SerializerMethodField()

    class Meta:
        model = InterestStatus
        fields = [
            'name',
            'interested_users_uids',
            'not_interested_users_uids',
        ]

    def get_interested_users_uids(self, obj):
        uuids = []
        if obj.get('annotated_interested_uids'):
            uuids = obj.get('annotated_interested_uids').split(',')
        return uuids

    def get_not_interested_users_uids(self, obj):
        uuids = []
        if obj.get('annotated_not_interested_uids'):
            uuids = obj.get('annotated_not_interested_uids').split(',')
        return uuids