This particular revival was I feel very welcome, the contributor @blueswan16 had something to say about his actual experiences with knives and compared them favourably to a very much more expensive brand, this adds to knowledge and opened the door to discussion about Grohmann- an underrated manufacturer in some peoples' eyes. So what if a thread is old ? If people can inject new life into it, add relevant comments about the knives plus newer pictures that's what a Forum is for. The poster is a very new member and it would be wrong to put him off by crying necromancy incautiously. The age of a thread is somewhat irrelevant, the content vital. There are threads that are chock a block with repetitions, multi quotes, thanks for your thanks, for your thanks, thanks ABC, or full of non knife content about daily trivia but they are not frowned upon.
Certainly, if a thread has been done to death, or if people add to it irrelevantly, or want to boost post counts then necromancy is wrong, in this case I feel it is not.