Link me to a page on Pixiv where a Japanese artist post only uncensored stuff. If it happens it's either:
1) they're currently living outside of Japan and they won't get in trouble for publishing uncensored stuff.
2) they're foreigners and they know Japanese.
3) they're foreigners and they used google translate for the title and description.
Either way, it's still violating the law, they're still considered insensitive to many Japanese that resides in Japan. That's why 99.99% of the time Japanese artists censor their stuff, it's not only to abide by the laws, it's the courtesy. You only ever see uncensored stuff if they're licensed to be sold in foreign market. I said the viewer could get in trouble for downloading uncensored porn, but it's unlikely they'll get caught, however, the case is not the same for the artist.
I saw many Japanese artists start publishing ??? (uncut/uncensored) these days on foreign websites such as patreon and gumroad, they get away with it most of the time because their target market is the non-Japanese people, but it's still considered a taboo.