Disclaimer: I don't know anything about pokemon itself. In particular, I don't know the answer to either of the two questions involved here, so I'm going to cover all possibilities.
If it's true that humans are immune to Pokemon attacks, then that (with canon evidence) would be the answer to your question and also the older question. In this case, we could potentially close the older question as a duplicate of yours, because "are handlers immune" is covered by the more general "are humans immune".
If handlers have some immunity but humans in general do not, then your question and the older question have two different answers, and neither of them should be closed as a duplicate of the other.
If not even handlers have protection from Pokemon attacks, then that (again, with canon evidence) would be the answer to the older question and would also resolve your question. In that case, we could potentially close your question as a duplicate of the older one which would solve it completely.
I don't know which of these three options is the case - and it seems neither does the site at large, so far. The only answer we have so far is sitting at a net -1 (at the time of writing), and it says "I believe within Pokémon canon Pokémon powers are simply ineffective against humans, so trainers need no special resistance." If true, this would be an answer to the question, but it's not really shown conclusively there, and the community doesn't seem to like this answer much.
So we're at the stage where there are two strongly related but slightly different questions. The answer to one of them might also answer the other, but we don't know for sure whether the correct answer to the older one will answer yours or not. Until we're sure, we should err on the side of leaving the questions open. Then if someone knows the answer, they can answer whichever one is likely to be the dupe target (as in, the correct answer to that one necessarily resolves the other one).
This specific case is a bit more complicated than just "are handlers immune" vs "are humans immune", because your question is not just an unrelated "are humans immune" but
specifically asking about a claim made in an answer to the older question.
If that answer is edited to include canon proof, then your question becomes completely obsolete and could indeed be closed. But if the answer is incorrect, then your question is a good one. We really need to wait and find out - but in the meantime, and in case the answerer doesn't return to edit their answer, there's no need to block your question from other answers.
Cf. the following hypothetical situations:
- I ask the question "Did Bellatrix Lestrange love Lord Voldemort?" and get an answer "Yes, because all Death Eaters loved Voldemort - it's part of the job description". That shouldn't be enough to close "Did Lucius Malfoy love Voldemort?" or "Did all Death Eaters love Voldemort?" as a duplicate, because that answer is not correct.
- I ask the question "Did Ron Weasley have two pets/familiars at the same time?" and get an answer "No, because Hogwarts students are allowed at most one [with evidence]", then a later question "Can Hogwarts students have more than one familiar?" would already be answered there (although I'd then argue for closing the specific case to the general, potentially merging to preserve answers).
