I've added several categories to my watchlist for the purpose of tracking when pages are added and removed from those categories. Some of these are tracking categories (some 'official' ones and some via templates).
The problem is, when a page move occurs that causes an add or remove from one of those categories, it doesn't appear as a changelist item in my watchlist.
Renaming a page usually doesn't change anything about the categories, except the category is set via a template, and the template decides to change the category based on the name of the page. But even that should work. Sorry, there is just not enough information to do anything with this ticket. If you have more information please feel free to re-open it.
Okay indeed it mostly works now, although it might have been different a few years ago. One case that's still problematic (i.e. doesn't seem to work) is when a user account is renamed, and the relevant user pages get moved. E.g. this change caused Category:Pages with ignored display titles to be added, but this isn't visible in my watchlist.