They don't. You can check Nuka's Texas Furry Fiesta 2013 talk, or check the IARP website, or ask Nuka directly. The subject wasn't developed further since then, because (as explained by Nuka in unpublished statements), it would be hard to scientifically / ethically justify, to higher boards, researching in that particular direction (other than as a mere curiosity for furries).

I believe cub 'haters', unfortunately, aren't aware of differences between ephebophilia (teens) and paedophilia (kids), even though one is arguably a lot more pathological than the other. In any case, they're both illegal if under the age of consent, to which the debate against cub art would relate.

A note of the sort "This artist does not wish his art to be distributed anywhere else" would be more explicit. All here respecfully following his wishes ourselves, someone else in the next 10 minutes would upload that same picture on e621.net (with or without Download button).

As explained in the Furry Network blog, I am confident their decision to disallow 'cub porn' was only partially if at all based on the number of votes that ticket had. It's a controversial issue with its downsides and considerations. You can read the details at the blog.

Even with many votes being 'fake' (something that should not be a problem now), it shows people are pretty passionate about their stance against cub porn. This is not new and in fact it is clearly reflected in furry surveys by the IARP, where art related to baby furs are far more disliked than anything else on the fandom.

Personally I have many more furry friends who are cub lovers than friends who are cub haters. But I would not easily host their art at my home or public space without pondering much if it's worth the trouble.

I thought this was already a feature by virtue of selecting General, Mature, or Explicit. If you wish to see the most agreeable art, you select General.

In any case, if this gets implemented (default blacklisting), I would like for this default blocking of particular fetishes deemed 'unworthy' to be notified to the user, or plain obvious in the settings panel. I hate it when websites take those kinds of decisions for me and I don't know about them.

Please yes. PNG transparency compliance should be a mandatory feature on any website at this point in time. I actually don't care about animated GIFs (a gimmick), but I do about transparency.

The artists' "choice" in this scenario is irrelevant. If you don't want people to download your art, you simply don't upload it to the internet. If I see your art and I want it, I'll fetch it from the browser cache, or any other simple procedure. Disabling a 'download' button will do nothing but annoy your viewers.