Angela wrote:
d) I don't see any reason for a merge but "merge and redirect" was the outcome of an AfD so I'd better chuck a {{merge}} template on it.
Articles listed for reason (d) are rather likely to stay in the backlog since they're on articles no one cares about which only narrowly survived deletion. Before those templates existed, people could [[WP:BB]] and redirect the page, but now it seems more common to use a template than to "fix" the problem. I don't know if this is a policy/guideline issue with people being obligated to add {{merge}} before doing so or just a cultural change where many editors no longer feel confident to "be bold in updating pages".
More likely just laziness and/or lack of time on behalf of the closing admins. Some merges can be non-trivial, and determining whether a given merge is trivial or not can itself take time. If you're already busy clearing a backlog of AfD closures, the temptation to just slap a merge tag on it and move on can be great.
The positive side here is that, since it's mostly an issue with admin behavior rather than that of random editors, it can be solved by coming up with a new recommended procedure and communicating it the admins doing the closures (via [[WP:AN]], this list, personal talk pages etc). The negative side is that any viable solution needs to ensure it doesn't just turn the merge backlog into an even bigger AfD closure backlog.
Some possible solutions I can think of off the top of my head include:
a) Advise admins to always perform the merge when closing, if at all possible. This could mean just cut-and-pasting the text and slapping a cleanup tag on it, but at least the merge itself would get done.
b) Suggest that busy admins just redirect the page to be merged and put a notice on the talk page of the target page with a link to the text to be merged. We could even make a special template for this. This will only take care of one half of "merge and redirect", but half done is better than nothing at all.
c) Make a new "afdmerge" template (or templates), for use in cases where the decision to merge has already been reached on AfD. This template would state that consensus has already been reached and would strongly recommend that anyone having the time to carry out the merge go ahead and do it.
None of these are, of course, mutually exclusive. If anyone can suggest other possible approaches, please do.