It’s quite details, but:
A) At the bottom of a lot of tracked topics, I see a line saying:
You will see a count of new replies because you [read this topic]
The link “read this topic” doesn’t work. It has the following structure: forum.domain.xxx/t/topic/u/user/preferences/notifications
I don’t know if that’s supposed to achieve something in particular or it’s a bug and the /t/topic part shouldn’t be there. Without it, you end up in the notifications portion of your preferences, and you can adjust the Automatically track topics I enter after x minutes and When I post in a topic, set that topic to. That may be the goal of this link. I’m not sure.
B) If I enter a topic and click to track it manually, it says the same. It would seem more logical to have a line telling me something like “You will see a count of new replies because you selected manually to track it”
Just FYI, for topics where I posted or which I created, the line is ending with “because you posted a reply to this topic/created this topic”, which is good. There is NO LINK in this case (there could be, as when “because you read”)
C) SPLIT Topics: I believe I noticed today that when a tracked topic is split, the tracking parameter is set on the split (“forked”) topic, which is good. But it seems Discourse lost the count of the actually read posts. It was only showing me the last answer as unread (and linking me to this one) when there was in fact more than that. This may be a little more complicated, and maybe “normal”. I also only had one occurrence of this, so I’m not 100% sure.