I don't want to have come off as having actual authority on the matter. What I described is how the sprite/icon/animation teams generally handle cases like this. Not sure how it translates to this project or how DJTHED feels about having outsiders' work being used in place of their own.
It's worth noting that
technically speaking, this project is not associated with Smogon or Showdown, this is
my project. If Showdown wanted to change how Pokemon are visually presented on what is their platform, that's something they can choose to do if they find someone else, that's not up to me. I'm just the Blender guy. I can still have my opinions on what they should do, but like I said, not up to me. The renders I make here I've always given permission to be used on Showdown should they choose to, and for anyone else who wants to use them too, but it's still technically my project.
I understand, but if someone went out of their way to make them and post them in the Smogon forums, doesn't that mean they are fine with them being used? If we were talking about something complex like, a piece of code or software, I understand not trusting it. But we can see the art moving and working perfectly fine.
Either way I really appreciate the hard work and I don't mean to question Pokémon Showdown's principles, I was just curious about it. Thank you for the answer!
As for them not using certain sprites/renders posted here, at least on the 3D side of things, I don't recall anyone stepping up to do them from someone who didn't turn out to be super sketchy with plagiarism or stealing someone elses work and not giving appropriate credit or permission. They may have claimed to have cleaned up their act and claimed to have started providing their own work, but this particular person most likely lost the trust of not just me, but those involved in making such decisions. If this was the contributor you saw and was referring to, that'd probably be why they were ignored, not because of if it was unsafe, just the lack of trust. As far as I am aware, there has been no other case where someone has contributed their own work and given permission, so I feel this is probably who you were referring to unless I'm missing something.