Would it make sense to require a reason from a user when voting to reopen a question if they haven't made any changes to the question?
This sounds intuitively like a good idea (more information is always better, right?) but:
The review process should be simple. Either the question is good (enough) for the site (Reopen), or it isn't (Leave Closed). If you're not sure, or have no strong opinion either way, click Skip. This is independent of whether it has been edited or not.
If the first Reopen voter had wished to convey some exceptional context ("I know a really great answer to this!"), he or she could have brought it up in chat, posted on meta, or even flagged the question for a moderator. None of that happened.
Requiring a reason would be tricky. "Should be reopened" would likely be a popular reason, as might "I like waffles". It might even dissuade someone from voting to reopen when they should, because it makes the process just that little bit more difficult, or they couldn't think of the right way to phrase a convincing reason.
Making it optional would simply mean adding system & task complexity for an edge case that might be useful as intended only very rarely. As mentioned, there are at least three channels already for exceptional situations.
To me, it doesn't seem worth the bother. I do worry that it could work against the interests of the site, by making it a little less likely that first reopen vote would be cast.