Well, I expect that Twitter will now be banned by every corporate filter in existence.
For the same reason we have spotify blocked at work, but not youtube because we publish our comms there. Which results in... people listening to music videos and wasting a ton of bandwidth for no reason (because they're downloading the video just for the music). A bit stupid but the powers that be are unwilling to unblock spotify.
But I don't think most people at the company care, they just want to listen and take whatever they know. I don't think most of them even know youtube music exists. Spotify is really popular here (Europe) but it's banned like I mentioned.
So I'm going to guess the workaround is that Apple requires NSFW content to not be accessible as a default, but does not get in the way for the content being accessible via some form of external switch. The 'external' requirement makes me think that maybe it's about shifting some sort of perceived liability? X might have to add a similar option I guess.