Yes, I just tested this on my local dev site and am finding the same thing. I think the issue is with the logic that’s used here:
Changing that line to topics = topics.where("topics.category_id NOT IN (?)", remove_category_ids) seems to fix the issue with categories that have been added to the digest_suppress_categories setting, but some logic for handling muted categories will need to be added. Maybe something like:
topics = topics.where("topics.category_id NOT IN (?)", remove_category_ids).where("topic_users.notification_level != (?)", TopicUser.notification_levels[:muted])