The person who filled the request is under no obligation to post it to the blog; and many have chosen not to post publicly - especially since the whole Renderhub tracking sales affair. When a request has been filled, and you missed out, you can create a new request for the item.
In the future, look for it at kemono.su (the website) or its alternate site, kemono.party . It can often be found there if it's on Patreon, Gumroad, Pixiv or the like.
Some people like to post stuff from Kemono to the main posts and harvest points; I consider that an IQ test to see who reads the forums, since most of it gets posted in the Free Resources section anyway.