Answering an unanswered question is definitely valid. Feedback for a niche creative project may be better served by a new post, but a late comment is fine as well.
I dont have a problem with necrobumping, but i dont think it deserves to be promoted or incentivesed in a “bestof5monthslater” showcase.
Anything that can be gamed for imaginary internet points will be abused, and it wont be long before there is a flood of “Upvote if your still reading in 2025 🥳🤠🤯” comments.