I know art exclusively involving humans have resulted in heated debates in the past and that, as the rules currently stand, content of that kind past a certain date isn't allowed.

As you may have guessed by the title, I'm curious if this if this also extends to humans wearing fake ears and tails. I ask because, although they aren't furry, they're not that far off in appearance from humanoids who have real ears and tails nor in concept from fursuiters.

This is kind of a tricky one. It really depends on how emphasized the furry part is, how many posts are coming in, how well the artist/franchise/fandom is established here, how good the art is, etc. For example, a post like post #621155 has a much better chance of getting accepted than a rating:safe post of Adventure Time chracters with fake ears and a tail or a post with humans holding a cat from an unknown artist that looks like a screencap from some anime. Some of these will probably be approved, but they might not.

Real stuff is generally discouraged whether it's merchandise, fursuiting, cosplay, etc. It's approved sometimes, but it's not hugely relevant to the site. Additionally, anything borderline sexual with cosplay will be handled slightly different as it's often impossible to verify the age of the person or if they even want the photo on here. Also, to be blunt people tend to upload a lot of crappy photos, which doesn't help much. :P

Granted, none of the above should be taken as official guidelines, as they are just based on patterns that I've noticed in the past (take a look at not_furry to get an idea of borderline cases). A slightly more official stance might be a better worded version of "Don't be surprised if they get deleted", but it's always going to be case-by-case.

A few of the first posts that I uploaded were real. They were deleted. And even though I thought they would work on this website, they didn't.

I've learned from that and have kept that in mind with what I've been uploading since.