The broad rule is: Do not close questions as duplicates if the target question does not help the new asker.
I understand that there is split opinion for support for this trial, and that is not what this discussion is really about. My concern is the aftermath of questions that become re-opened by request of the user.
In the link above you will find some examples of questions that have been marked as duplicates and then re-opened. For some re-opened questions you will find that an answer is provided and can justify that the two linked questions are in fact unique questions.
For other questions I can see the following process:
- A question is marked as a duplicate (because, word for word, it has already been asked directly or indirectly via another question)
- The OP says the answers do not help so it is reopened by way of this new trial
- An answer is provided
In terms of the What is the "regional Pokemon" for south America? question specifically (and I am sure there will be others like this) the answer to the new question can be incorporated into the original question.
At this point (assuming the original question has an updated and/or new answer) we can now mark the new question as a duplicate.
The overall outcome is we have a duplicate question, and an update to the original question's answer.
This may have occurred previous to the trial, but probably not without a meta saying the answer doesn't help, possibly a bounty on the original question and possibly some extensive comment/chat within the original or duplicate question.
Is this outcome the intention of the trial? I didn't see this specifically addressed in the above meta link or here: Duplicate Questions: A New Look
If this is intentional it would be beneficial to detail the expected process a little further than the "vote to re-open" stage. I could be wrong, but I believe that some people who prefer the old system may foresee questions that have been re-opened staying open (when all that was really needed was a better answer to the original question).