I posted a handful of images today at the request of an artist and 2 of the 5 have been removed because they were sketches of a single human. There are hundreds of other images already posted that also fall into this category and so I am left wondering if there was another reason for this deletion.

P.S. if this is the incorrect place to bring this up, could someone please direct me to the proper method.

most human_only post are super old and were posted before the posting rules were made more strict and they are just grandfathered in.

That doesn't seem to be the case when I look at their upload age...

Can you cite your examples of "human only" images? There is little to no context in your statement, I'm fairly certain your examples can be explained on a post-to-post basis.

7thUmbra said:
That doesn't seem to be the case when I look at their upload age...

there's also the ones that are in pools or have parent / child posts that feature non-humans on other pages and/or feature tranformation

there are also posts containing tentacles which are allowed

the wiki page and uploading guidelines explain this

7thUmbra said:
That doesn't seem to be the case when I look at their upload age...

These posts may have been updated because their better versions were found later and so they were replaced recently. Updating a post that was grandfathered in and allowed at the time isn't the same as posting new, previously unuploaded content no longer allowed.

7thUmbra said:
That doesn't seem to be the case when I look at their upload age...

Always reflect upon uploading guidelines, not on other approved posts. If we started to evaluate all posts based on thousands and millions of other posts every time we would get nowhere.
Guidelines change over time and mistakes can happen even to the best.

This is also why guidelines specifically mention grandfathered posts and posts that are part of e.g. pool, because we have accepted and can accept humans, but there's conditions and they have changed over time. Currently if you upload post with no characters or only character that falls under human definion, it will get deleted as irrelevant.

Also as tip for checking if the post has been replaced with superior copy, search with parent:<ID> status:any and it will show all the deleted posts under that post. Of course if unsure you can bring IDs of posts you see to be againts the guidelines during their posting time and we can give them a gander, instead of pointing fingers at omnious direction and yelling "but they are doing it".