By default bluesky blocks adult content, once you enable it you can dial in what kind of adult content you wish to see. I know this is all anecdotal, like the links you posted... But I started a new account to see what it's like. I can scroll the default algorithm for 5 minutes and not see anything questionable, and my actual account exists with adult content turned on and I never see it. After signing up the new account, I can search for furry or diaper content, but it appears that none of it is like "nsfw" (mostly just people in furry costumes or diapers but no sexual content or nudity).

Just to solidify, I just went and created a new account to ensure I was right, and I was. You need to go to your settings, go to moderation, and enable adult content. I scrolled continuously for 5 minutes straight and saw no adult content on a default account. And on top of this, as far as I can google, Bluesky has never had adult content enabled by default, so if you are seeing it, you enabled it.