When a post is moved to a new topic, the followers (those who watched the topic) of the original topic becomes automatically followers of the new topic (the moved reply).
while the notification level for the new topic should be set to Normal for users other than the original poster.
This is by design, @gerhard recently worked on this. The users expressed the will to watch the original topic so we assume they want to watch the new topic.
I can argue that most of the times, they don’t. because the new topic is something that doesn’t fit in the old one, otherwise it won’t get moved into a new topic.
maybe I’m using a wrong word/context. their criticism was of course for us, and not to discourse. what they have said to us was this:
we feel that you are not respecting our interests, and you’ve forced us to follow some topics from specific users*!
{*we have 2-3 specific users with extra activity in our forum, who sometimes start extra discussion in a topic and we need to move their replies into a new discussion!}
It seems there is only two options on the table, new way or old way, but in both ways the system decides.
I know there are holes in the following ideas, but it is just a compass bearing and not a detailed map.
Perhaps instead of the system deciding a new user option is added that allows a user to decide when a post is moved if they follow those post automatically (I think of this as the passive option).
Another option is that they are prompted when they visit either topic again and choose which of the post they want to continue to be notified. (I think of this as the active option).
I think that subscribing to the new post all users that have been subscribed to the original post is the correct solution, as it is now.
The users have not control of when an admin or mod can split a thread.
If they are interested in the theme of the post that is split, and they are not subscribed to it, they miss the opportunity to read what other people has to say, or even read that post if it is spitted before they read it, so they cannot know if it is of interest for them or not.
If they are subscribed to it and they are not interested, they always have te opportunity of unsubscribing from it.